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    As filed with the Securities and Exchange Commission on September 7, 2001
                                                      Registration No. 333-
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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

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                        Advanced Energy Industries, Inc.
             (Exact name of registrant as specified in its charter)

           Delaware                                             84-0846841
(State or other jurisdiction of                              (I.R.S. Employer
 incorporation or organization)                             Identification No.)

              1625 Sharp Point Drive, Fort Collins, Colorado 80525
         (Address, including zip code, of principal executive offices)

                             1995 Stock Option Plan
                            (Full title of the plan)

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

                                RICHARD P. BECK
                        ADVANCED ENERGY INDUSTRIES, INC.
                             1625 SHARP POINT DRIVE
                          FORT COLLINS, COLORADO 80525
                                 (970) 221-4670
            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)

                            ------------------------
                                   COPIES TO:
                               CARISSA C. W. COZE
                            THELEN REID & PRIEST LLP
                             333 SOUTH GRAND AVENUE
                              LOS ANGELES, CA 90071

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                        CALCULATION OF REGISTRATION FEE


===================================== ================= ================== ===================== ===================
     Title of securities to be           Amount to be    Proposed maximum     Proposed maximum        Amount of
            registered                  registered (1)    offering price     aggregate offering    registration fee
                                                           per share (2)         price (2)
- ------------------------------------- ----------------- ------------------ --------------------- -------------------
                                                                                     
Common Stock, $0.001 par value.......      2,500,000          $22.89            $57,225,000           $14,306.25
===================================== ================= ================== ===================== ===================

(1)  The maximum number of additional shares of Common Stock to be offered under
     the 1995 Stock Option Plan. Does not include 5,625,000 previously
     registered shares offered or to be offered under such plan.
(2)  Estimated solely for the purpose of determining the registration fee in
     accordance with Rule 457(h) under the Securities Act of 1933, as amended.
     The above calculation is based on the average of the reported high and low
     prices of the Common Stock on the Nasdaq National Market on August 31,
     2001.


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          INCORPORATION OF EARLIER REGISTRATION STATEMENT BY REFERENCE

     This registration statement is filed to register 2,500,000 shares of common
stock of Advanced Energy Industries, Inc., which shares are authorized to be
issued pursuant to the 1995 Stock Option Plan, as amended. A registration
statement on Form S-8 (File No. 333-01616) with respect to 3,500,000 shares of
common stock authorized to be issued pursuant to the plan was filed on February
23, 1996; a registration statement on Form S-8 (File No. 333-57233) with respect
to 1,125,000 shares of common stock authorized to be issued pursuant to the plan
was filed on June 19, 1998 and a registration statement on Form S-8 (File No.
333-79425) with respect to 1,000,000 shares of common stock authorized to be
issued pursuant to the plan was filed on May 27, 1999. Except for Part II, Items
3, 6, 8 and 9, which are set forth below, the contents of such earlier
registration statements are hereby incorporated by reference.

                                     PART II
               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference

     The documents listed below, which we have filed with the Securities and
Exchange Commission, are specifically incorporated by reference into this
registration statement and form an integral part of this registration statement.
Information in documents that we file with the Securities and Exchange
Commission subsequent to the date of this registration statement will
automatically update and supercede the information contained in the listed
documents, until we file a post-effective amendment to this registration
statement that either indicates that all securities covered by this registration
statement have been sold or deregisters all securities unsold as of the date of
the post-effective amendment.

          (a) Annual Report on Form 10-K for the year ended December 31, 2000,
filed March 27, 2001 (File No. 000-26966);

          (b) All other reports filed by us pursuant to Section 13(a) or 15(d)
of the Securities Exchange Act of 1934 (the "Exchange Act"), since the end of
the fiscal year covered by document referred to in (a) above; and

          (c) The description of our common stock contained in the registration
statement on Form 8-A filed under the Exchange Act on October 12, 1995,
including any amendment or report filed for the purpose of updating such
description.

Item 6.  Indemnification of Directors and Officers

          As permitted by the Delaware General Corporation Law ("GCL"), the
registrant's Restated Certificate of Incorporation, as amended ("Certificate"),
provides that no director shall be personally liable to the registrant or any
stockholder for monetary damages for breach of fiduciary duty as a director,
except for liability: (i) for any breach of the duty of loyalty to the
registrant or its stockholders; (ii) for acts or omissions not in good faith or
involving intentional misconduct or a knowing violation of the law; (iii)
arising from payment of dividends or approval of a stock purchase in violation
of Section 174 of the GCL; or (iv) for any action from which the director
derived an improper personal benefit. While the Certificate provides protection


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from awards for monetary damages for breaches of the duty of care, it does not
eliminate the director's duty of care. Accordingly, the Certificate will not
affect the availability of equitable remedies, such as an injunction, based on a
director's breach of the duty of care. The provisions of the Certificate
described above apply to officers of the registrant only if they are directors
of the registrant and are acting in their capacity as directors, and does not
apply to officers of the registrant who are not directors.

          In addition, the registrant's By-laws provide that the registrant
shall indemnify its Executive Officers (as defined in Rule 3b-7 promulgated
under the Exchange Act) and directors, and any employee who serves as an
Executive Officer or director of any corporation at the registrant's request, to
the fullest extent permitted under and in accordance with the GCL; provided,
however, that the registrant may modify the extent of such indemnification by
individual contracts with its Executive Officers and directors; and, provided
further, that the registrant shall not be required to indemnify any Executive
Officer or director in connection with any proceeding (or part thereof)
initiated by such person unless: (i) such indemnification is expressly required
to be made by law; (ii) the proceeding was authorized by the directors of the
registrant; (iii) such indemnification is provided by the registrant, in its
sole discretion, pursuant to the powers vested in the registrant under the GCL;
or (iv) such indemnification is required to be made under Article XI, Section
43, Subsection (d) of the registrant's By-Laws. Under the GCL, directors and
officers as well as employees and individuals may be indemnified against
expenses (including attorneys' fees), judgments, fines and amounts paid in
settlement in connection with specified actions, suits or proceedings, whether
civil, criminal, administrative or investigative (other than an action by or in
the right of the corporation as a derivative action) if they acted in good faith
and in a manner they reasonably believed to be in or not opposed to the best
interests of the corporation, and with respect to any criminal action or
proceeding, had no reasonable cause to believe their conduct was unlawful.

          The registrant maintains a policy of directors' and officers'
liability insurance that insures the registrant's directors and officers against
the cost of defense, settlement or payment of a judgment under certain
circumstances.

Item 8.  Exhibits

          Exhibit
          Number    Description
          ------    -----------

           4.1      Restated Certificate of Incorporation, as amended
                    (incorporated by reference to our quarterly report on Form
                    10-Q for the quarter ended June 30, 2001, File No.
                    000-26966, filed August 13, 2001.)

           4.2      Bylaws (incorporated by reference to our registration
                    statement on Form S-1, File No. 33-97188, filed September
                    20, 1995, as amended)

           5.1      Opinion of Counsel


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          Exhibit
          Number    Description
          ------    -----------

          23.1      Consent of Counsel (included in Exhibit 5)

          23.2      Consent of Arthur Andersen LLP

            24      Powers of Attorney (included on the signature pages to this
                    registration statement)

Exhibit 9.  Undertakings

          (a) The undersigned registrant hereby undertakes:

               (1) To file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement;

                    (i) To include any prospectus required by Section 10(a)(3)
of the Securities Act of 1933, as amended (the "Securities Act");

                    (ii) To reflect in the prospectus any facts or events
arising after the effective date of this registration statement (or the most
recent post-effective amendment thereof) which, individually or in the
aggregate, represent a fundamental change in the information set forth in this
registration statement. Notwithstanding the foregoing, any increase or decrease
in volume of securities offered (if the total dollar value of securities offered
would not exceed that which was registered) and any deviation from the low or
high end of the estimated maximum offering range may be reflected in the form of
prospectus filed with the Commission pursuant to Rule 424(b) if, in the
aggregate, the changes in volume and price represent no more than a 20% change
in the maximum aggregate offering price set forth in the "Calculation of
Registration Fee" table in the effective registration statement;

                    (iii) To include any material information with respect to
the plan of distribution not previously disclosed in this registration statement
or any material change to such information in this registration statement;

provided however, that paragraphs (a)(1)(i) and (a)(1)(ii) shall not apply if
the information required to be included in a post-effective amendment by such
paragraphs is contained in one or more periodic reports filed with or furnished
to the Commission by the registrant pursuant to Section 13 or 15(d) of the
Exchange Act that are incorporated by reference in this registration statement.

               (2) That, for the purpose of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof; and


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               (3) To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

          (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act that is incorporated by reference in the registration statement
shall be deemed to be a new registration statement relating to the securities
offered therein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereof.

          (h) Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the registrant pursuant to the foregoing provisions, or otherwise,
the registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.


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                                   SIGNATURES

          Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Fort Collins, State of Colorado, on the 7th day of
September, 2001.

                                        Advanced Energy Industries, Inc.


                                        By:  /s/ Richard P. Beck
                                           ------------------------------------
                                           Richard P. Beck
                                           Senior Vice President and Chief
                                             Financial Officer


                                POWER OF ATTORNEY

          Each person whose signature appears below hereby appoints Douglas S.
Schatz and Richard P. Beck, and each of them severally, acting alone and without
the other, his true and lawful attorney-in-fact with authority to execute in the
name of each such person, and to file with the Securities and Exchange
Commission, together with any exhibits thereto and other documents therewith,
any and all amendments (including without limitation post-effective amendments)
to this registration statement necessary or advisable to enable the registrant
to comply with the Securities Act of 1933 and any rules, regulations and
requirements of the Securities and Exchange Commission in respect thereof, which
amendments may make such changes in this registration statement as the aforesaid
attorney-in-fact deems appropriate.

          Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed below by the following persons on behalf
of the registrant and in the capacities and on the dates indicated.


Dated:  September 7, 2001           /s/ Douglas S. Schatz
                                    -------------------------------------------
                                    Douglas S. Schatz
                                    Chairman of the Board and Chief
                                      Executive Officer
                                    (Principal Executive Officer)


Dated:  September 7, 2001           /s/ Richard P. Beck
                                    -------------------------------------------
                                    Richard P. Beck
                                    Senior Vice President and Chief Financial
                                      Officer and Director
                                    (Principal Financial and Accounting Officer)


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Dated:  September 7, 2001           /s/ G. Brent Backman
                                    -------------------------------------------
                                    G. Brent Backman
                                    Director


Dated:  September 7, 2001           /s/ Trung T. Doan
                                    -------------------------------------------
                                    Trung T. Doan
                                    Director


Dated:  September 7, 2001           /s/ Arthur A. Noeth
                                    -------------------------------------------
                                    Arthur A. Noeth
                                    Director


Dated:  September 7, 2001           /s/ Elwood Spedden
                                    -------------------------------------------
                                    Elwood Spedden
                                    Director


Dated:  September 7, 2001           /s/ Gerald M. Starek
                                    -------------------------------------------
                                    Gerald M. Starek
                                    Director


Dated:  September 7, 2001           /s/ Arthur W. Zafiropoulo
                                    -------------------------------------------
                                    Arthur W. Zafiropoulo
                                    Director


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                                  EXHIBIT INDEX

Exhibit
Number    Description
- ------    -----------

 4.1      Restated Certificate of Incorporation, as amended (incorporated by
          reference to our quarterly report on Form 10-Q for the quarter ended
          June 30, 2001, File No. 000-26966, filed August 13, 2001.)

 4.2      Bylaws (incorporated by reference to our registration statement on
          Form S-1, File No. 33-97188, filed September 20, 1995, as amended)

 5.1      Opinion of Counsel

23.1      Consent of Counsel (included in Exhibit 5)

23.2      Consent of Arthur Andersen LLP

  24      Powers of Attorney (included on the signature pages to this
          registration statement)