Disclosure of Equity Participation Pursuant to the Swiss Stock Exchange Act

Bad Ragaz / Switzerland - June 3, 2009 - INFICON Holding AG (SIX Swiss Exchange: IFCN), a leading, worldwide manufacturer of instrumentation and process control software for advanced industrial vacuum processes, today announced that Beat Frey owns as economic beneficiary through KWE Beteiligungen AG, c/o Corisol Holding AG, Grafenaustrasse 15, 6300 Zug (contact person Beat Frey, +41 (0)41 760 3026) a total of 338,195 registered shares of INFICON Holding AG since a purchase on May 29, 2009. This represents 15.76% of the voting rights in INFICON Holding AG.