Exhibit 32.1


      CERTIFICATION OF CHIEF EXECUTIVE OFFICER AND CHIEF FINANCIAL OFFICER
                                   PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


I, John D.  Heaton,  certify,  pursuant to 18 U.S.C.  Section  1350,  as adopted
pursuant to Section 906 of the  Sarbanes-Oxley  Act of 2002,  that the Quarterly
Report of Nanometrics Incorporated on Form 10-Q/A for the quarterly period ended
April 3, 2004 fully complies with the  requirements of Section 13(a) or 15(d) of
the  Securities  Exchange  Act of 1934 and that  information  contained  in such
Quarterly  Report on Form 10-Q/A  fairly  presents in all material  respects the
financial condition and results of operations of Nanometrics Incorporated.




Date: August 23, 2004               By: /s/ John D. Heaton
                                       -----------------------------------------
                                    Name:      John D. Heaton
                                    Title:     Chief Executive Officer




I, Paul B.  Nolan,  certify,  pursuant  to 18 U.S.C.  Section  1350,  as adopted
pursuant to Section 906 of the  Sarbanes-Oxley  Act of 2002,  that the Quarterly
Report of Nanometrics Incorporated on Form 10-Q/A for the quarterly period ended
April 3, 2004 fully complies with the  requirements of Section 13(a) or 15(d) of
the  Securities  Exchange  Act of 1934 and that  information  contained  in such
Quarterly  Report on Form 10-Q/A  fairly  presents in all material  respects the
financial condition and results of operations of Nanometrics Incorporated.



Date: August 23, 2004               By: /s/ Paul B. Nolan
                                       -----------------------------------------
                                    Name:      Paul B. Nolan
                                    Title:     Chief Financial Officer


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