EXHIBIT 10.29


                       FIRST AMENDMENT TO CREDIT AGREEMENT

         This FIRST AMENDMENT TO CREDIT AGREEMENT (this "First Amendment"),
dated as of February 5, 2002, is among CABOT MICROELECTRONICS CORPORATION, a
Delaware corporation (the "Company"), the financial institutions parties to the
Credit Agreement described below, as Banks thereunder, LASALLE BANK NATIONAL
ASSOCIATION, in its capacity as Administrative Agent and Issuing Bank under such
Credit Agreement, and NATIONAL CITY BANK OF MICHIGAN/ILLINOIS, in its capacity
as Syndication Agent under such Credit Agreement.

                                    RECITALS

         A. The Company, the Banks, the Administrative Agent, the Issuing Bank
and the Syndication Agent entered into a Credit Agreement dated as of July 10,
2001 (the "Credit Agreement"), pursuant and subject to the terms and conditions
of which, among other things, the Banks and the Issuing Bank agreed to make
loans and other financial accommodations to the Company.

         B. The Company has requested certain other amendments to the Credit
Agreement.

         C. Subject to the terms and conditions of this First Amendment, the
Banks, the Administrative Agent, the Issuing Bank and the Syndication Agent are
willing to agree to the requests of the Company.

         NOW, THEREFORE, in consideration of the mutual agreements contained
herein, and subject to the terms and conditions hereof, the parties hereto
hereby agree as follows:

         1. INCORPORATION OF RECITALS. The Recitals set forth above are
incorporated herein, are acknowledged by the Company to be true and correct and
are made a part hereof.

         2. DEFINITIONS. All capitalized terms used but not elsewhere defined
herein shall have the respective meanings ascribed to such terms in the Credit
Agreement, as amended by this First Amendment.

         3. AMENDMENTS TO CREDIT AGREEMENT. The Credit Agreement is amended by
deleting Section 7.4 in its entirety and substituting the following therefor:

                  "7.4 WAIVER OF SETOFF RIGHTS. The Administrative Agent, the
         Issuing Bank, the Syndication Agent, each Bank and the Company each
         hereby affirmatively waive all rights of set-off provided by applicable
         law with regard to any claim arising under or with respect to this
         Credit Agreement and their respective obligations hereunder. Without
         limiting the generality of the foregoing, the Administrative Agent and
         each Bank acknowledge and agree that none of them will apply to the
         payment of any obligations of the Company hereunder, whether or not due
         and whether or not any Event of Default exists, any balances, credits,
         deposits, accounts or moneys of the Company now or hereafter maintained
         with the Administrative Agent or such Bank or, in the absence of any
         order, decree, garnishment, injunction or other decision in a legal
         process or proceeding to the contrary, prohibit or freeze access to
         such balances, credits, deposits, accounts or moneys."




         4. CONDITIONS TO EFFECTIVENESS. The effectiveness of this First
Amendment shall be subject to the satisfaction of all of the following
conditions in a manner, form and substance satisfactory to the Administrative
Agent.

         (A) DELIVERY OF DOCUMENT. This First Amendment shall have been executed
by the Company, Syndication Agent and each Bank and shall have been delivered to
the Administrative Agent.

         (B) PERFORMANCE; NO DEFAULT. The Company shall have performed and
complied with all agreements and conditions contained in the Loan Documents to
be performed by or complied with by it, and no Event of Default or Unmatured
Event of Default shall exist.

         (C) MATERIAL ADVERSE EFFECT. No event shall have occurred since
September 30, 2001 which has had or is reasonably expected to have a Material
Adverse Effect.

         The date on which all of the conditions set forth in this Paragraph 4
have been satisfied is referred to herein as the "Effective Date."

         5. REFERENCES. From and after the Effective Date, all terms used in the
Loan Documents which are defined in the Credit Agreement shall be deemed to
refer to such terms as amended by this First Amendment.

         6. REPRESENTATIONS AND WARRANTIES. The Company represents and warrants
to the Banks, the Administrative Agent, the Syndication Agent and the Issuing
Bank that (i) the Company has full power and authority to execute and deliver
this First Amendment and to perform its obligations hereunder, (ii) upon the
execution and delivery hereof, this First Amendment will be valid, binding and
enforceable upon the Company in accordance with its terms, (iii) the execution
and delivery of this First Amendment does not and will not contravene, conflict
with, violate or constitute a default under (A) its articles of incorporation or
by-laws or (B) any applicable law, rule, regulation, judgment, decree or order
of any agreement, indenture or instrument to which the Company is a party or is
bound or which is binding upon or applicable to all or any portion of the
Company's properties or assets and (iv) as of the date hereof no Unmatured Event
of Default or Event of Default exists.

         7. NO FURTHER AMENDMENTS; RATIFICATION OF LIABILITY. Except as amended
hereby, the Credit Agreement and each of the other Loan Documents shall remain
in full force and effect in accordance with its respective terms. The Company
hereby ratifies and confirms its liabilities, obligations and agreements under
the Credit Agreement and the other Loan Documents, all as amended by this First
Amendment, and acknowledges that (i) it has no defenses, claims or set-offs to
the enforcement by the Banks, the Administrative Agent, the Syndication Agent or
the Issuing Bank of such liabilities, obligations and agreements, (ii) the
Banks, the Administrative Agent, the Syndication Agent and the Issuing Bank have
fully performed all obligations to the Company which they have had had or have
on and as of the date hereof and (iii) other than as specifically set forth
herein, the Banks, the Administrative Agent, the Syndication Agent and the
issuing Bank do not waive, diminish or limit any term or condition contained in
the Credit Agreement or the Loan Documents. The agreement of the Banks, the
Administrative Agent,




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the Syndication Agent and the Issuing Bank to the terms of the First Amendment
or any other amendment of the Credit Agreement shall not be deemed to establish
or create a custom or course of dealing among the Banks, the Administrative
Agent, the Syndication Agent, the Issuing Bank and the Company. The Loan
Documents, as amended by this First Amendment, contain the entire agreement
among the Banks, the Administrative Agent, the Syndication Agent and the Issuing
Bank with respect to the transactions contemplated hereby.

         8. COUNTERPARTS. This First Amendment may be executed in one or more
counterparts, each of which shall be deemed an original, and all of which, when
taken together, shall constitute one and the same instrument.

         9. FURTHER ASSURANCES. The Company will at any time and from time to
time do, execute, acknowledge and deliver, or will cause to be done, executed,
acknowledged and delivered, all such further acts, documents and instruments as
reasonably may be required by the Banks, the Administrative Agent, the
Syndication Agent or the Issuing Bank in order to effectuate fully the intent of
this First Amendment.

         10. SEVERABILITY. If any term or provision of this First Amendment or
the application thereof to any part or circumstance shall be held to be invalid,
illegal or unenforceable in any respect by a court of competent jurisdiction,
the validity, legality and enforceability of the remaining terms and provisions
of this First Amendment shall not in any way be affected or impaired thereby,
and the affected term or provision shall be modified to the minimum extent
permitted by law so as most fully to achieve the intention of this First
Amendment.

         11. CAPTIONS. The captions in this First Amendment are inserted for
convenience of reference only and in no way define, describe or limit the scope
or intent of this First Amendment or any of the provisions hereof.

                (remainder of this page intentionally left blank)




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         IN WITNESS WHEREOF, this First Amendment has been executed and
delivered by each of the parties hereto by a duly authorized officer of each
such part on the date first set forth above.

                  CABOT MICROELECTRONICS CORPORATION


                  By: /s/ Martin M. Ellen
                     --------------------------
                     Martin M. Ellen
                     Chief Financial Officer



                  LASALLE BANK NATIONAL ASSOCIATION,
                  as Administrative Agent, as Issuing Bank and as a Bank


                  By: /s/ Jeffrey A. Raider
                     --------------------------
                     Jeffrey A. Raider
                     Senior Vice President


                  NATIONAL CITY BANK OF MICHIGAN/ILLINOIS,
                  as Syndication Agent and as a Bank

                  By: /s/ James M. Wilber
                     --------------------------
                     James M. Wilber
                     Vice President


                  FIRSTAR BANK, N.A., as a Bank


                  By: /s/ Timothy A. Fossa
                     --------------------------
                     Timothy A. Fossa
                     Vice President



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                                  SCHEDULE 2.1

                            BANKS AND PRO RATA SHARES


- ----------------------------------------------------------------------------
                                               PRO RATA SHARE
                                                OF REVOLVING        PRO RATA
                  BANK                        COMMITMENT AMOUNT      SHARE
- ----------------------------------------------------------------------------
LaSalle National Bank                             $30,000,000         40%
- ----------------------------------------------------------------------------
National City Bank of Michigan/Illinois           $22,500,000         30%
- ----------------------------------------------------------------------------
Firstar Bank, N.A.                                $22,500,000         30%
- ----------------------------------------------------------------------------
                          TOTALS                  $75,000,000        100%
- ----------------------------------------------------------------------------



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