EXHIBIT 10.13


                       AMENDMENT NO. 5 TO CREDIT AGREEMENT

         This Amendment No. 5 to Credit Agreement (this "Amendment") is made as
of this 4th day of May, 2000 by and among:

         VEECO INSTRUMENTS INC., a corporation organized under the laws of the
State of Delaware (the "Borrower"); and

         FLEET BANK, N.A., a national banking association organized under the
laws of the United States ("Fleet") and THE CHASE MANHATTAN BANK, a New York
banking corporation ("Chase", collectively with Fleet, the "Banks").

                                    RECITALS:

         (A) The Borrower and the Banks are parties to a Credit Agreement dated
as of July 31, 1996, as amended by Amendment No. 1 to Credit Agreement, dated
June 25, 1997, Amendment No. 2 to Credit Agreement, dated as of January 31, 1999
and Amendment No. 3 and Waiver to Credit Agreement, dated March 3, 2000 and
Amendment No. 4 to Credit Agreement, dated May 4, 2000 (the Credit Agreement as
so amended being hereinafter referred to as the "Credit Agreement");

         (B) The Borrower has requested, subject to the terms and conditions of
this Amendment, to amend certain provisions of the Credit Agreement and the
Banks are willing to amend such provisions of the Credit Agreement as set forth
herein; and

         (C) Any capitalized items not defined herein shall have the meanings
ascribed thereto in the Credit Agreement,

         NOW, THEREFORE, the parties hereto hereby agree as follows:

ARTICLE 1.  AMENDMENTS TO CREDIT AGREEMENT.

         This Amendment shall be deemed to be an amendment to the Credit
Agreement and shall not be construed in any way as a replacement or substitute
therefore. All of the terms and provisions of this Amendment are hereby
incorporated by reference into the Credit Agreement as if such terms and
provisions were set forth in full therein.

         SECTION 1.1. Section 7.10 of the Credit Agreement is hereby amended and
restated to provide in its entirety as follows:


         SECTION 7.10. SUBSIDIARIES. Within 10 Banking Days of their becoming
         Material Domestic Subsidiaries, cause all such Material Domestic
         Subsidiaries to become Guarantors hereunder and to deliver to the Banks
         executed Guarantees and, if the Aggregate Outstandings plus the
         aggregate principal balance of all Term Loans shall have at any time
         equaled or exceeded $25,000,000, deliver to the Banks an executed
         Pledge Agreement relating to the capital stock of each Domestic
         Subsidiary that is or that




         becomes a Material Domestic Subsidiary to the Collateral Agent,
         together with the Certificates evidencing the capital stock of each
         such Material Domestic Subsidiary.

         SECTION 1.2. Article 7 of the Credit Agreement is hereby amended by
inserting a new Section 7.12 at the end thereof which provides in its entirety
as follows:

             Section 7.12. CVC INDEBTEDNESS. Cause the revolving credit facility
         under the Loan Agreement dated March 31, 1998, as amended, between CVC
         Products, Inc. and Manufacturers and Traders Trust Company to be
         terminated on or before November 4, 2000.

         SECTION 1.3. Section 8.2 of the Credit Agreement is hereby amended by
deleting clause (l) thereof in its entirety and substituting in its place the
following:

         "(l) Liens securing Indebtedness, to the extent permitted pursuant to
         Section 8.1(i) and other than Liens that are permitted pursuant to
         subparagraphs (a) through (k) of this Section 8.2, provided that (x)
         the Liens attach solely to the assets of the Borrower or the Subsidiary
         which is the obligor with respect to such Indebtedness; (y) such Liens
         do not secure any Indebtedness other than the Indebtedness permitted
         pursuant to Section 8.1(i) and (z) such Liens, without including, for
         purposes of this subparagraph (z) only, the Liens securing Indebtedness
         existing at the time of the acquisition of CVC, Inc. and its
         Subsidiaries, as more fully described on Schedule 8.2(l) (the "CVC
         Liens"), do not secure greater than $10,000,000, in the aggregate, of
         the assets of the Borrower or such Subsidiary which is the obligor;
         provided further that such Liens, other than the CVC Liens, are
         terminated or released within six months of the Closing Date of such
         Permitted Acquisition."

         SECTION 1.4. Schedule 8.2(l) attached hereto shall be deemed to be
Schedule 8.2(l) to the Credit Agreement.

         SECTION 1.5. Article 9 of the Credit Agreement is hereby amended by
inserting the following sentence at the end thereof:

         Compliance with each of the foregoing covenants, other than the
         covenant set forth in Section 9.3, shall be determined without giving
         effect to the one-time charge against earnings of $33,000,000 taken by
         the Company in connection with the acquisition of CVC, Inc.

ARTICLE 2.  REPRESENTATIONS AND WARRANTIES.

         The Borrower hereby represents and warrants to the Banks that:

         SECTION 2.1. After giving effect to this Amendment, each and every one
of the representations and warranties set forth in the Credit Agreement is true
in all material respects as of the date hereof with respect to the Borrower and,
where applicable, the Guarantors with the same

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effect as though made on the date hereof (unless such representation or
warranty is limited by its terms to an earlier date), and is hereby incorporated
herein in full by reference as if fully restated herein in its entirety.

         SECTION 2.2. After giving effect to this Amendment, no Default or Event
of Default, as defined in the Credit Agreement, now exists.

         SECTION 2.3. No representation, warranty or statement by the Borrower
or the Guarantors contained herein or in any other document to be furnished by
the Borrower or the Guarantors in connection herewith contains, or at the time
of delivery shall contain, any untrue statement of material fact, or omits or at
the time of delivery shall omit to state a material fact necessary to make such
representation, warranty or statement not misleading.

         SECTION 2.4. Each of the Facility Documents, other than the Security
Agreements and the Pledge Agreements, continues to be in full force and effect
and, with respect to the Guarantees, secure all payment and other obligations of
the Borrower under the Credit Agreement.

ARTICLE 3. MISCELLANEOUS.

         This Amendment shall be governed by and construed in accordance with
the laws of the State of New York.

         IN WITNESS WHEREOF, each of the undersigned has executed or caused to
be duly executed this Amendment as of the date first above written.

                                              VEECO INSTRUMENTS INC.

                                              By:  /s/ AUTHORIZED SIGNATORY
                                                   ----------------------------
                                              Name:
                                              Title:


                                              FLEET BANK, N.A.

                                              By:    /s/ AUTHORIZED SIGNATORY
                                                     ---------------------------
                                              Name:  Christopher Mendelsohn
                                              Title: Vice President


                                              THE CHASE MANHATTAN BANK

                                              By:     /s/ AUTHORIZED SIGNATORY
                                                      --------------------------
                                              Name:   Carolyn B. Lattanzi
                                              Title:  Vice President


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The undersigned, not parties to the Credit Agreement but as Guarantors
under Guarantees executed in favor of the Bank, each hereby accept and agree to
the terms of the foregoing Amendment.

                                              WYKO CORPORATION

                                              By:    /s/ AUTHORIZED SIGNATORY
                                                     --------------------------
                                              Name:
                                              Title:


                                              SLOAN TECHNOLOGY CORP.

                                              By:    /s/ AUTHORIZED SIGNATORY
                                                     ---------------------------
                                              Name:
                                              Title:


                                              VEECO INDUSTRIAL MEASUREMENT, LLC
                                              By:  Veeco Instruments Inc., its
                                                   Sole Member

                                              By:    /s/ AUTHORIZED SIGNATORY
                                                     --------------------------
                                              Name:
                                              Title:


                                              VEECO METROLOGY, LLC
                                              By: Veeco Instruments Inc., its
                                                  Sole Member

                                              By:    /s/ AUTHORIZED SIGNATORY
                                                     -------------------------
                                              Name:
                                              Title:


                                              ION TECH, INC.

                                              By:    /s/ AUTHORIZED SIGNATORY
                                                     --------------------------
                                              Name:
                                              Title:


                                              TULAKES REAL ESTATE INVESTMENTS,
                                              INC.

                                              By:   /s/ AUTHORIZED SIGNATORY
                                                    ---------------------------
                                              Name:
                                              Title:

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                                               VEECO MINNEAPOLIS TECHNOLOGY
                                               CENTER INC.

                                               By:   /s/ AUTHORIZED SIGNATORY
                                                    ---------------------------
                                               Name:
                                               Title:




                                                CVC, INC.

                                                By:  /s/ AUTHORIZED SIGNATORY
                                                     --------------------------
                                                Name:
                                                Title:


                                                CVC PRODUCTS, INC.

                                                By:   /s/ AUTHORIZED SIGNATORY
                                                       -------------------------
                                                Name:
                                                Title:


                                                COMMONWEALTH SCIENTIFIC
                                                CORPORATION

                                                By:   /s/ AUTHORIZED SIGNATORY
                                                       -------------------------
                                                Name:
                                                Title:



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                                 SCHEDULE 8.2(l)

Liens on the assets of CVC, Inc. and/or its Subsidiaries which Liens
existed at the time of the acquisition of CVC, Inc. by the Borrower.












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