February 8 2006 Disclosure of Equity Participations Pursuant to the Swiss Stock Exchange Act

Syracuse, New York/Zurich, Switzerland — February 8, 2006 — INFICON Holding AG (SWX Swiss Exchange: IFCN), a leading manufacturer of vacuum instrumentation and process control software for the semiconductor and related industries and other industrial applications, today announced that according to a notification received from Bank Julius Baer & Co. Ltd. Zurich, their equity participation in INFICON Holding AG exceeded the reporting threshold of 5% on February 8, 2006 with 131,880 registered shares at CHF 10 par value each. This represented 5.69 % of the voting rights in INFICON Holding AG.

Corporate Contact
Betty Ann Kram
Director of Corporate Communications
and Investor Relations
+1.315.434.1122
BettyAnn.Kram@inficon.com

European Contact
Bernhard Schweizer
sensus PR GmbH
+41.43.366.5511
bschweizer@sensus.ch