[LOGO] INFICON
                                                                    Exhibit 99.1



                                                   
Corporate Contact          European Contact              North American Contact
Betty Ann Kram             Bernhard Schweizer/Sara Koch  Jody Burfening/Kathy Price
Director of Corporate      c-matrix group ag             Lippert/Heilshorn & Associates, Inc.
Communications             +41 (0) 41.769.80.40          +1.212.838.3777
and Investor Relations     inficon@cmatrix.ch            jbs@lhai.com
+1.315.434.1122
BettyAnn.Kram@inficon.com



Disclosure of Equity Participations pursuant to the Swiss Stock Exchange Act

Syracuse, New York/Zurich, Switzerland -- August 27, 2003 -- INFICON Holding AG
(SWX Swiss Exchange and NASDAQ: 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 FMR Corp, Boston/USA, the parent company of
Fidelity Management & Research Company, the equity participation of FMR Corp in
INFICON Holding AG is now 232'543 shares with a par value of CHF 10 each,
representing 10.05% of the voting rights in INFICON Holding AG.