1 EXHIBIT 23.1 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in Registration Statements Nos. 33-31298, 33-85020 and 333-39499 of Silicon Valley Group, Inc. on Forms S-8 of our reports dated October 27, 1997 appearing in and incorporated by reference in this Annual Report on Form 10-K of Silicon Valley Group, Inc. for the year ended September 30, 1997. /s/ Deloitte & Touche LLP - ------------------------- DELOITTE & TOUCHE LLP San Jose, California December 29, 1997