EXHIBIT 21 LIST OF SUBSIDIARIES OF KLA INSTRUMENTS CORPORATION STATE OR OTHER JURISDICTION OF NAME INCORPORATION - ---- --------------- KLA Building Corporation California KLA Instruments International Corporation California KLA International Corporation California KLA Management Corporation California KLA Instruments PCBI Corporation California KLA Instruments Limited United Kingdom KLA Instruments GmbH Germany KLA Instruments France, S.A. France KLA Japan Limited Japan KLA Instruments Sales Corporation U.S. Virgin Islands KLA Instruments, SLR Italy KLA Instruments (Israel) Corporation Israel KLA Holding Company Limited Israel KLA (Israel) Service Limited Israel KLA Instruments (Cayman) Limited Cayman Islands KLA Instruments KLINNIK Corporation California KLA Instruments, S.A. Switzerland KLA Instruments (Malaysia) SdnBdh Malaysia KLA Instruments (Singapore) PTE, Limited Singapore Metrologix, Inc. Delaware The aforesaid subsidiaries do business only under their own names. 17