Disclosure of Equity Participation Pursuant to the Swiss Stock Exchange Act

Bad Ragaz / Switzerland — January 4, 2012 — 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 according to a notification signed on December 27, 2011, a newly defined group of people consisting of Beat Frey, Brigitte Frey, Vanessa Frey and Alexandra Frey own as economic beneficiaries through KWE Beteiligungen AG, c/o Corisol Holding AG, Grafenaustrasse 15, 6300 Zug (contact person Vanessa Frey, +41 (0)41 760 3028) a total of 440,482 registered shares of INFICON Holding AG. This represents 20.25% of the voting rights in INFICON Holding AG. At the same time KWE Beteiligungen AG with the indirect holder Beat Frey has reduced the voting rights in INFICON Holding AG below the 3% threshold.