EXHIBIT 23.1 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in Registration Statement Nos. 33-43913, 333-33583 and 333-40866 of Nanometrics Incorporated on Form S-8 of our reports dated February 13, 2002, appearing in this Annual Report on Form 10-K of Nanometrics Incorporated for the year ended December 31, 2001. Deloitte & Touche LLP San Jose, California March 15, 2002 IV-5