1
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                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                            ------------------------

                                    FORM 11-K

                                  ANNUAL REPORT
                        PURSUANT TO SECTION 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934


   (MARK ONE)
   [X]   ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT
         OF 1934 [NO FEE REQUIRED, EFFECTIVE OCTOBER 7, 1996].

                           FOR THE FISCAL YEAR ENDED DECEMBER 31, 1999

                                       OR

   [ ]   TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE
                                   ACT OF 1934
         [NO FEE REQUIRED].

                          COMMISSION FILE NUMBER 1-9965


A.    Full title of the plan and the address of the plan, if different from that
      of the issuer named below:

                           KEITHLEY INSTRUMENTS, INC.
                        RETIREMENT SAVINGS TRUST AND PLAN

B.    Name of issuer of the securities held pursuant to the plan and the address
      of its principal executive office:

                           KEITHLEY INSTRUMENTS, INC.
                                28775 AURORA ROAD
                                SOLON, OHIO 44139

   2










                           KEITHLEY INSTRUMENTS, INC.

                        RETIREMENT SAVINGS TRUST AND PLAN

                              FINANCIAL STATEMENTS

                            AND SUPPLEMENTAL SCHEDULE

                                    * * * * *

                           DECEMBER 31, 1999 AND 1998














   3
                           KEITHLEY INSTRUMENTS, INC.

                        RETIREMENT SAVINGS TRUST AND PLAN

                          INDEX TO FINANCIAL STATEMENTS

                            AND SUPPLEMENTAL SCHEDULE



                                                                         PAGE
                                                                         ----

Report of independent accountants                                          1

Financial statements:

     Statement of Net Assets Available for
       Plan Benefits as of December 31, 1999 and 1998                      2

     Statement of Changes in Net Assets Available for
       Plan Benefits for the year ended December 31, 1999                  3

     Notes to financial statements                                        4-9

Supplemental schedule:

     Schedule of assets held for investment purposes
       at December 31, 1999                                           Schedule I












NOTE: Certain schedules required under the Department of Labor Rules and
      Regulations for Reporting and Disclosure under the Employee Retirement
      Income Security Act of 1974 have been omitted as the conditions under
      which they are required are not present.


   4
                        REPORT OF INDEPENDENT ACCOUNTANTS


June 16, 2000

To the Participants and Administrator
   of the Keithley Instruments, Inc.
   Retirement Savings Trust and Plan

In our opinion, the accompanying statement of net assets available for plan
benefits and the related statement of changes in net assets available for plan
benefits present fairly, in all material respects, the net assets available for
plan benefits of the Keithley Instruments, Inc. Retirement Savings Trust and
Plan (the "Plan") at December 31, 1999 and 1998, and the changes in net assets
available for plan benefits for the year ended December 31, 1999 in conformity
with accounting principles generally accepted in the United States. These
financial statements are the responsibility of the Plan's management; our
responsibility is to express an opinion on these financial statements based on
our audits. We conducted our audits of these statements in accordance with
auditing standards generally accepted in the United States which require that we
plan and perform the audit to obtain reasonable assurance about whether the
financial statements are free of material misstatement. An audit includes
examining, on a test basis, evidence supporting the amounts and disclosures in
the financial statements, assessing the accounting principles used and
significant estimates made by management, and evaluating the overall financial
statement presentation. We believe that our audits provide a reasonable basis
for the opinion expressed above.

Our audits were performed for the purpose of forming an opinion on the basic
financial statements taken as a whole. The supplemental Schedule of Assets Held
for Investment Purposes is presented for the purpose of additional analysis and
is not a required part of the basic financial statements but is supplemental
information required by the Department of Labor's Rules and Regulations for
Reporting and Disclosure under the Employee Retirement Income Security Act of
1974. The supplemental schedule is the responsibility of the Plan's management.
The supplemental schedule has been subjected to the auditing procedures applied
in the audit of the basic financial statements and, in our opinion, is fairly
stated in all material respects in relation to the basic financial statements
taken as a whole.


/s/ PricewaterhouseCoopers LLP


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                           KEITHLEY INSTRUMENTS, INC.

                        RETIREMENT SAVINGS TRUST AND PLAN

               STATEMENT OF NET ASSETS AVAILABLE FOR PLAN BENEFITS

                        AS OF DECEMBER 31, 1999 AND 1998



                                                                1999                     1998
                                                            -----------              -----------

                                                                               
Investments, at fair value (cost of investments totaled
     $29,016,200 and $24,770,989 for the years ended
     December 31, 1999 and 1998, respectively)              $37,089,148              $28,967,999

Participants' loans                                             215,510                  267,478
                                                            -----------              -----------

                   Total investments                         37,304,658               29,235,477
                                                            -----------              -----------

Receivables:
     Employer contribution                                      327,831                   85,786
     Participant contributions                                  239,506                  124,537
                                                            -----------              -----------
           Total receivables                                    567,337                  210,323

Cash                                                            213,307                    2,969
                                                            -----------              -----------

     Net assets available for plan benefits                 $38,085,302              $29,448,769
                                                            ===========              ===========







The accompanying notes are an integral part of the financial statements.


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                           KEITHLEY INSTRUMENTS, INC.

                        RETIREMENT SAVINGS TRUST AND PLAN

         STATEMENT OF CHANGES IN NET ASSETS AVAILABLE FOR PLAN BENEFITS

                      FOR THE YEAR ENDED DECEMBER 31, 1999



                                                                             1999
                                                                         -----------
                                                                      
     Additions:
       Investment income:
         Net appreciation on investments                                 $ 4,696,373
         Dividends and capital gains                                       2,872,441
         Other income                                                        367,458
         Interest                                                             23,129
                                                                         -----------
               Total investment income                                     7,959,401
                                                                         -----------

       Contributions:
         Employer                                                            567,336
         Participants                                                      1,751,211
                                                                         -----------
               Total contributions                                         2,318,547

               Total additions                                            10,277,948
                                                                         -----------

       Deductions:
         Distributions to participants                                     1,639,114
         Asset-based fees                                                      2,301
                                                                         -----------
               Total deductions                                            1,641,415
                                                                         -----------

               Net increase                                                8,636,533

Net assets available for plan benefits at beginning of year               29,448,769
                                                                         -----------

Net assets available for plan benefits at end of year                    $38,085,302
                                                                         ===========



The accompanying notes are an integral part of the financial statements.


   7
                               KEITHLEY INSTRUMENTS, INC.

                            RETIREMENT SAVINGS TRUST AND PLAN

                              NOTES TO FINANCIAL STATEMENTS


NOTE 1 - PLAN DESCRIPTION:

The following description of the Keithley Instruments, Inc. Retirement Savings
Trust and Plan (the "Plan") provides only general information. Participants
should refer to the Plan agreement for a more complete description of the Plan's
provisions.

     Participation

The Plan is a defined contribution plan, established on January 1, 1988,
covering all domestic employees of Keithley Instruments, Inc. and its
participating subsidiaries (the "Company") who have attained age twenty-one. The
Plan is subject to the provisions of the Employee Retirement Income Security Act
of 1974 (ERISA).

     Administration

The Plan is administered by the Company (the "Administrator"). The
administration of the Plan includes exercising all necessary powers as provided
by the Plan to interpret and apply the Plan provisions. The Company is vested
with the right to settle claims or debts and to defend any claims arising from
the operation of the Plan. Schwab Retirement Services, Inc. ("Schwab") is the
trustee and acts as the custodian of the Plan.

     Contributions

Participants may elect to contribute up to 15 percent of their compensation and
have the option of contributing their profit sharing award, if any, on a pre-tax
basis subject to certain limitations of the Plan. In 1999, the Company paid a
profit sharing award, which some employees decided to contribute to the Plan. It
is the Company's policy to match at least $.25 of each dollar contributed,
limited to six percent of a participant's compensation during the Plan year.
Additionally, it is the Company's policy to match up to a maximum of $.50 of
each dollar contributed, limited to six percent of a participant's compensation
for the Plan year, based upon the Company's financial performance. For 1999 and
1998, the Company's match was $.50 and $.30 on each dollar contributed by
participants up to six percent of a participant's compensation, respectively.
The Company has complete discretion to determine its matching contribution, if
any, each year.



   8
     Participant accounts

Each participant has two separate accounts under each fund in which
contributions have been invested on behalf of the participant. One account
represents the participant's contributions and earnings thereon ("Participant
Account") and the other account represents the employer's contributions, made on
behalf of the respective participant, and the earnings thereon ("Employer
Account"). Forfeitures of terminated participants' nonvested account balances
are used to reduce future employer contributions.

Net assets available for Plan benefits of $16,804 and $13,445 were not allocated
to participants' accounts at December 31, 1999 and 1998, respectively, due to
forfeitures during each Plan year.

     Vesting

Participants are immediately vested in their voluntary contributions plus
earnings thereon. Vesting of the employer contributions starts after the first
year and is based on years of service. A participant is 100 percent vested after
three years of credited service.

     Payment of benefits

Upon termination of service, a participant may elect to receive either a
lump-sum amount equal to the value of his or her account, or installment
payments. In the case of a severe financial hardship, the Administrator at its
sole discretion may direct an earlier distribution of all or a portion of a
participant's account, subject to certain restrictions.

     Loans

In the case of a financial hardship as defined by the Plan, a participant may
apply to the Administrator for a loan. The Administrator in accordance with a
uniform nondiscriminatory policy, may direct the custodian to make a loan to a
participant from their before-tax contribution account, subject to certain
restrictions. Loans outstanding as of December 31, 1999 and 1998, bear interest
rates ranging from 8-11 percent per annum.

     Termination provisions

The Company anticipates and believes that the Plan will continue indefinitely;
however, the Company reserves the right to terminate the Plan at any time by an
action of its Board of Directors. In the event of termination of the Plan, the
assets then remaining will be allocated and distributed to participants in
accordance with the terms and provisions of the Plan.



   9
     Use of estimates

The preparation of financial statements in conformity with accounting principles
generally accepted in the United States requires Plan management to make
estimates and assumptions that affect the reported amounts of net assets
available for Plan benefits and disclosure of contingent assets and liabilities
at the date of the financial statements and the reported amounts of changes in
net assets available for Plan benefits during the reporting period. Actual
results could differ from those estimates.


NOTE 2 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES:

     Contributions and benefit distributions

Matching contributions from the Company are recognized during the period in
which they are earned. Distributions are recognized during the period in which
they are paid to a Plan participant.

     Investment valuation and income recognition

All investment accounts are included in the financial statements at fair value
determined by quoted market prices as reported to the Plan by Schwab. Purchases
and sales of securities are recorded on a trade-date basis. Interest income is
recorded on the accrual basis. Dividends are recorded on the ex-dividend date.
Realized gains or losses on security transactions are recorded in an amount
equal to the difference between net proceeds received and the revalued cost at
the date of sale and are reflected in the Statement of Changes in Net Assets
Available for Plan Benefits.

The Plan presents in the Statement of Changes in Net Assets Available for Plan
Benefits the net appreciation in the fair value of its investments which
consists of the realized gains or losses and the unrealized appreciation or
depreciation on those investments.

     Administrative expenses

Participation fees are paid by the Company. Asset-based fees are paid by the
participants.


   10
NOTE 3 - INVESTMENTS:

During 1999, 12 funds were available to participants for investment purposes.
Schwab manages the distribution of assets among funds and provides recordkeeping
services. Following is a description of each fund:

Schwab Stable Value Fund - This fund invests primarily in insurance company
guaranteed investment contracts and arrangements commonly known as synthetic
investment contracts, and other investments which seek to maintain principal
value, protect against market volatility, obtain consistent income return and
provide reasonable liquidity. Such transactions qualify as party in interest. At
December 31, 1999, there were approximately 360 participants invested in this
fund.

Invesco Total Return Fund - This fund invests in a combination of equities and
investment-grade fixed-income securities and seeks capital appreciation and
current income. The fund maintains at least 30% of its assets in equities, and
at least 30% in fixed and variable rate debt securities. The fund may invest up
to 25% of assets in foreign securities. At December 31, 1999, there were
approximately 220 participants invested in this fund.

Aim Charter Fund - This fund invests a substantial portion of its assets in
dividend-paying common stocks. No more than 10% of the fund's stocks may be in
securities that are not currently paying dividends. The fund may invest in
various short-term debt securities for liquidity or defensive purposes. It may
invest up to 10% of assets in American depositary receipts, and another 10% in
direct foreign securities. At December 31, 1999, there were approximately 290
participants invested in this fund.

Twentieth Century Select Fund - This fund normally invests at least 80% of
assets in dividend-paying common stocks; however, these securities are chosen
primarily for their growth potential. The fund intends to remain fully invested
in stocks, regardless of the movement of stock prices generally. This fund may
also invest without limit in foreign securities, including American depositary
receipts. At December 31, 1999, there were approximately 290 participants
invested in this fund.

Fidelity Magellan Fund - This fund invests primarily in common stocks and
convertible securities. Up to 20% of its assets may be invested in debt
securities of all types and qualities. The fund invests in domestic and foreign
companies. There is no limitation on total foreign investment, but no more than
40% of the fund's assets may be invested in companies operating exclusively in
one foreign country. At December 31, 1999, there were approximately 325
participants invested in this fund.

Twentieth Century Growth Fund - This fund normally invests substantially all
assets in equity securities of large, established companies that meet its
standards of earnings and revenue growth. However, it may hold up to 10% of
assets in cash. The fund may only purchase securities of companies with at least
three years of operations, and may invest in foreign securities without limit,
including American depositary receipts. At December 31, 1999, there were
approximately 290 participants invested in this fund.

T. Rowe Price Science & Technology Fund - This fund normally invests at least
65% of assets in companies, both foreign and domestic, that seek to develop or
use scientific and technological advances. Industries include computers and
peripheral, software, electronics, pharmaceutical and medical devices,
telecommunications, biotechnology, waste management, chemicals, synthetic
materials, defense and aerospace. These holdings may include both new and
established companies. At December 31, 1999, there were approximately 290
participants invested in this fund.

   11
T. Rowe Price New Horizons Fund - This fund invests primarily in common stocks
of small, rapidly growing companies. Management concentrates on companies that
may offer accelerating earnings growth because of new management, new products,
or structural changes in the economy. The fund may invest up to 10% of assets in
foreign securities, including American depositary receipts. At December 31,
1999, there were approximately 145 participants invested in this fund.

Scudder Global Fund - This fund invests in companies expected to benefit from
global economic trends, promising technologies or specific country
opportunities. It is expected that investments will be spread broadly around the
world, including the United States, in companies of varying sizes. The fund
generally invests in the equity securities of established companies listed on
foreign securities exchanges. At December 31, 1999, there were approximately 130
participants invested in this fund.

Vanguard Index Extended Market Fund - This fund invests in a statistically
selected sample of the stocks included in the Wilshire 4500 Index. This index
consists of more than 5,000 primarily smaller to medium-sized common stocks
traded on the NYSE, AMEX or listed on the NASDAQ. These stocks are not included
in the S&P 500 Index. At December 31, 1999, there were approximately 120
participants invested in this fund.

UAM FMA Small Company Portfolio Fund - This fund invests at least 65% of assets
in common stocks issued by U.S. companies with market capitalizations of $50
million to $1 billion. When selecting securities, the advisor looks for
companies with low P/E ratios, strong cash flows, good credit lines, and
improving balance sheets. The fund may invest up to 10% of assets in foreign
securities. At December 31, 1999, there were approximately 75 participants
invested in this fund.

Personal Choice Retirement Account - This fund provides for self-directed
investing whereby each participant may choose to invest in any stock listed on a
major U.S. exchange, over 1,200 mutual funds, bonds and other fixed-income
investments, and money market funds. At December 31, 1999, there were
approximately 15 participants invested in this fund.



   12
The following table presents the fair value of the individual investments that
represent 5 percent or more of the Plan's net assets:

                                                         December 31,
                                                 1999                    1998
                                              ----------              ----------

Schwab Stable Value Fund                      $6,068,851              $5,329,028
Invesco Total Retuen Fund                      1,876,522               2,427,358
Aim Charter Fund                               5,300,431               4,108,685
Twentieth Century Select Fund                  5,224,957               4,533,679
Twentieth Century Growth Fund                  4,402,998               3,411,401
Fidelity Magellan Fund                         5,429,758               4,195,673
T. Rowe Price Science & Technology Fund        4,464,347               1,752,302

The aggregate proceeds from transactions in the Plan's mutual fund investments
was $7,288,896 for the year ended December 31, 1999. The related cost of these
transactions was $6,968,304, resulting in a realized gain totaling $320,592 for
the year ended December 31, 1999. Realized gains and losses on investments are
included in the caption Net appreciation on investments in the Statement of
Changes in Net Assets Available for Plan Benefits.

Cost is determined using the revalued cost method. Unrealized appreciation on
Plan assets was $4,375,781 and $2,962,334 for the years ended December 31, 1999
and 1998.

NOTE 4 - FEDERAL INCOME TAX STATUS:

On February 13, 1996, the Internal Revenue Service advised that the Plan, as
amended, is qualified and the trust thereunder is exempt from federal income tax
pursuant to Section 401(a) of the Internal Revenue Code (IRC). The Plan has been
amended since receiving the determination letter. However, the Plan's
administrator and the Plan's tax counsel believe that the plan is designed and
is currently being operated in compliance with the applicable requirements of
the IRC.

NOTE 5 - RECENT ACCOUNTING PRONOUNCEMENTS

In September 1999, the Financial Accounting Standards Board issued Statement of
Position 99-3, "Accounting for Reporting of Certain Defined Contribution Plan
Investments and Other Disclosure Matters" ("SOP 99-3"), which changed the
presentation of the Statement of Changes in Net Assets Available for Plan
Benefits, eliminating the requirement to present earnings and expenses by
investment fund. The Plan adopted SOP 99-3 for the Plan year end December
31,1999. The December 31, 1998 financial statements have been conformed to the
SOP 99-3 presentation for comparability purposes.


   13
                                                                     Schedule I
                                                                     Page 1 of 3

                           KEITHLEY INSTRUMENTS, INC.
                        RETIREMENT SAVINGS TRUST AND PLAN
      SCHEDULE OF ASSETS HELD FOR INVESTMENT PURPOSES AT DECEMBER 31, 1999



(a)      (b) Identity of Issue                                                (c) Number of Shares/Units        (e) Current Value
- ---      --- -----------------                                                --- ----------------------        --- -------------

                                                                                                       
         Cash                                                                                                       $     213,307
*        Schwab Stable Value Fund                                                                499,819                6,068,851
         Invesco Total Return Fund                                                                64,797                1,876,522
         Aim Charter Fund                                                                        286,820                5,300,431
         Twentieth Century Select Fund                                                            99,183                5,224,957
         Fidelity Magellan Fund                                                                   39,741                5,429,758
         Twentieth Century Growth Fund                                                           136,400                4,402,998
         T. Rowe Price Science & Technology Fund                                                  70,073                4,464,347
         T. Rowe Price New Horizons Fund                                                          37,979                1,045,555
         Scudder Global Fund                                                                      28,299                  883,494
         Vanguard Index Extended Market Fund                                                      24,103                  893,486
         UAM FMA Small Company Portfolio Fund                                                     18,415                  258,544
         Personal Choice Retirement Account:
              Cash and Equivalents                                                                                        180,951
              Common Stocks:
                  Actel Corp.                                                                        500                   12,000
                  Albertsons, Inc.                                                                   807                   26,047
                  Alottafun, Inc.                                                                    250                      172
                  Applied Micro Circuits Corp.                                                       150                   19,088
                  At Home Corp. Class A                                                              300                   12,863
                  Bank One Corp                                                                      810                   25,920
                  Banta Corp.                                                                        509                   11,486
                  Brush Wellman, Inc.                                                              1,000                   16,813
                  Cadence Design Systems, Inc.                                                       500                   12,000
                  CHS Electronics, Inc.                                                            1,000                    1,125
                  Cohu, Inc.                                                                       1,600                   49,600
                  Compaq Computer Corp.                                                              250                    6,766
                  Com21, Inc.                                                                      1,000                   22,438
                  Cutter & Buck, Inc.                                                              3,275                   49,533
                  CVS Corp.                                                                          802                   31,995
                  Cypress Semiconductor Corp.                                                        150                    4,856
                  Dell Computer Corp.                                                                250                   12,750
                  First Sec Corp.                                                                    750                   19,148
                  Gliatech, Inc.                                                                     200                    3,325
                  Home Depot, Inc.                                                                   150                   10,340
                  IFR Systems Inc.                                                                 2,000                   20,124
                  IOMega Corp.                                                                       500                    1,688
                  J P M Company                                                                      200                    1,575
*                 Keithley Instruments, Inc.                                                      13,695                  279,045
                  Keycorp, Inc.                                                                       50                    1,106



   14
                                                                     Schedule I
                                                                     Page 2 of 3
                           KEITHLEY INSTRUMENTS, INC.
                        RETIREMENT SAVINGS TRUST AND PLAN
      SCHEDULE OF ASSETS HELD FOR INVESTMENT PURPOSES AT DECEMBER 31, 1999



(a)      (b) Identity of Issue                                                (c) Number of Shares/Units         (e) Current Value
- ---      --- -----------------                                                --- ----------------------         --- -------------

                                                                                                        
                  Komag                                                                              100                       313
                  Kulicke & Soffa Industries, Inc.                                                   300                    12,769
                  Lucent Technologies                                                                165                    12,382
                  Mattson Technology, Inc.                                                           400                     6,850
                  National Semiconductor Corp.                                                     1,000                    42,812
                  NCS Healthcare, Inc. Class A                                                     4,000                     9,625
                  Officemax, Inc.                                                                  3,000                    16,313
                  Pairgain Technologies                                                              500                     7,094
                  PictureTel Corp.                                                                   525                     2,264
                  PMC-Sierra, Inc.                                                                   100                    16,031
                  Reliant Energy, Inc.                                                                51                     1,162
                  RF Micro Devices, Inc.                                                             100                     6,844
                  Solectron Corp.                                                                    245                    23,306
                  Spyglass, Inc.                                                                     100                     3,792
                  State Street Corp.                                                                 400                    29,224
                  Steris Corp.                                                                       500                     5,125
                  Sterling Commerce                                                                  900                    30,600
                  Tyco International Ltd.                                                            200                     7,800
                  United Parcel Service Class B                                                      100                     6,900
                  Varco International, Inc.                                                          200                     2,038
                  Vishay Intertechnology, Inc.                                                       656                    20,746
                  Zoltek Companies, Inc.                                                             100                       863
                  Zoom Telephonics, Inc.                                                             200                     1,688
                                                                                                                           -------

                  Total Common Stocks                                                                                      918,344
                                                                                                                           -------

              Mutual Fund:
                  Firsthand Communication                                                            185                     2,710
                  Firsthand E-Commerce Fund                                                          300                     4,464
                  Firsthand Technology Innovators Fund                                                72                     3,572
                  Firsthand Technology Leaders Fund                                                   90                     4,035
                  Firsthand Technology Value Fund                                                     79                     7,118
                  Invesco Technology II                                                              189                    15,287
                  Janus Enterprise Fund                                                               39                     3,026
                  Janus Global Technology Fund                                                        92                     2,831
                  Midas Fund                                                                      27,919                    37,970
                  Munder Netnet Fund Class A                                                          34                     2,561


   15
                                                                     Schedule I
                                                                     Page 3 of 3

                           KEITHLEY INSTRUMENTS, INC.
                        RETIREMENT SAVINGS TRUST AND PLAN
      SCHEDULE OF ASSETS HELD FOR INVESTMENT PURPOSES AT DECEMBER 31, 1999



(a)      (b) Identity of Issue                                                (c) Number of Shares/Units         (e) Current Value
- ---      --- -----------------                                                --- ----------------------         --- -------------

                                                                                                        
                  Profundsultraotc Fund                                                              254                    25,108
                  Vanguard Capital Opportunity Fund                                                1,092                    26,223
                  Vanguard Growth Index Fund                                                         152                     6,005
                                                                                                                         ---------

         Total Personal Choice Retirement Account                                                                        1,240,205
                                                                                                                         ---------

         Participant Loans, interest rates from 8 to 11% per
         annum                                                                                                             215,510
                                                                                                                         ---------


(*) Denotes an allowable party in interest.



   16
                                   SIGNATURES

The Plan. Pursuant to the requirements of the Securities Exchange Act of 1934,
the trustees (or other persons who administer the employee benefit plan) have
duly caused this annual report to be signed on its behalf by the undersigned
hereunto duly authorized.

                                      KEITHLEY INSTRUMENTS, INC.
                                      RETIREMENT SAVINGS TRUST AND PLAN
                                                 (Name of Plan)


Date:  June 27, 2000                  /s/ Mark J. Plush
                                      ------------------------------------------
                                      Mark J. Plush
                                      Vice President and Chief Financial Officer
                                      Keithley Instruments, Inc.