MENLO PARK, CA, OCTOBER 4, 2006 —Ultra Clean Holdings, Inc. (Nasdaq: UCTT), the parent company of Ultra Clean Technology Systems and Service, Inc., will release third quarter 2006 financial results on Monday, October 23, 2006 after markets close.

The Company will host a conference call to discuss third quarter 2006 financial results and management's outlook at 2:00 pm PST on Monday, October 23, 2006. The call-in number is 800/709-0218 (domestic) and 212/231-2661(international). A replay of the conference will be available for fourteen days following the call at 800/633-8284 (domestic) and 402/977-9140 (international). Confirmation number for live broadcast and replay is 21305979 (all callers).

Ultra Clean will also webcast the conference call live on our website at www.uct.com under Investor Relations.