April 18 2008 Disclosure of Equity Participation Pursuant to the Swiss Stock Exchange Act

Syracuse, New York / Zurich, Switzerland — April 18, 2008 — INFICON Holding AG (SWX Swiss Exchange: IFCN), a leading, worldwide manufacturer of instrumentation and process control software for advanced industrial vacuum processes, today announced, that Polar Capital LLP, 4 Matthew Parker Street, London SW1H 9NP (Contact: Gopal Bharj) disclosed on April 18, 2008, that its Polar Capital Forager Fund, domiciled at the same above-mentioned address, held 76,064 registered shares of INFICON Holding AG at CHF 5 par value each since a purchase on March 7, 2008. This represents 3.199% of the voting rights in INFICON Holding AG.