EXHIBIT 99.1


                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with this annual report on Form 10-K/A of Electro Scientific
Industries, Inc. (the "Company") for the annual period ended June 1, 2002 as
filed with the Securities and Exchange Commission on the date hereof (the
"Report"), I, Barry L. Harmon, President and Chief Executive Officer of the
Company, certify, pursuant to 18 U.S.C. ss. 1350, as adopted pursuant to ss. 906
of the Sarbanes-Oxley Act of 2002, that to the best of my knowledge:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of
the Securities Exchange Act of 1934; and
(2) The information contained in the Report fairly presents, in all material
respects, the financial condition and results of operations of the Company.


/s/ Barry L. Harmon
- --------------------------
Barry L. Harmon
President and Chief Executive Officer
August 11, 2003

This certification is made solely for the purpose of 18 U.S.C. Section 1350, and
not for any other purpose. A signed original of this written statement required
by Section 906 has been provided to Electro Scientific Industries, Inc. and will
be retained by Electro Scientific Industries, Inc. and furnished to the
Securities and Exchange Commission or its staff upon request.