FORM 6-K

                        SECURITIES & EXCHANGE COMMISSION

                             Washington, D.C. 20549

                        Report of Foreign Private Issuer

                        Pursuant to Rule 13a-16 or 15d-16

                     Of the Securities Exchange Act of 1934

                               September 30, 2004

                               INFICON Holding AG

                              INFICON Holding Inc.
                 (Translation of registrant's name into English)

                                  INFICON Inc.

                              Two Technology Place

                          East Syracuse, New York 13057
                    (Address of principal executive offices)

           (Indicate by check market whether the registrant files or
          will file annual reports under cover Form 20-F or Form 40-F.)

                           Form 20-F [X] Form 40-F [ ]

        (Indicate by check mark whether the registrant by furnishing the
          information contained in this Form is also thereby furnishing
          the information to the Commission pursuant to Rule 12g3-2(b)
                under the Securities Exchange Act of 1934.)

                                 Yes [ ] No [X]




Enclosure: Press release dated September 30, 2004, Inficon Revises Third Quarter
2004 Outlook

                                   Signatures

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.

Date:  September 30, 2004          INFICON Holding AG


                                   By: /s/ Peter G. Maier
                                       -----------------------------------------
                                       Name: Peter G. Maier
                                       Title: Vice President and Chief Financial
                                              Officer



             INFICON Revises Third Quarter 2004 Outlook;
       Regular Quarterly Earnings Conference Call Scheduled for
                           October 21, 2004

    SYRACUSE, N.Y. & ZURICH, Switzerland--(BUSINESS WIRE)--Sept. 30,
2004--INFICON (SWX Swiss Exchange and NASDAQ: IFCN), a leading
manufacturer of vacuum instrumentation and process control software
for the semiconductor and vacuum-coating industries and other
industrial applications, today announced that it expects to report
revenue of approximately $42 million and a net loss of approximately
$0.8 million ($0.34 per diluted share - $0.03 per ADS) for the third
quarter ended September 30, 2004. This includes a $1.5 million charge
on disposal of discontinued operations, related primarily to a
valuation allowance on deferred tax assets associated with its
Patterning Solutions business. This compares to earlier guidance for
revenue of approximately $47 million and net income of approximately
$2.3 million ($1.00 per diluted share - $0.10 per ADS).
    The company attributed the revenue shortfall primarily to a delay
in large orders for HAPSITE, its chemical identification detector,
from the U.S. Department of Defense, reflecting slower-than-expected
government procurement processes, and also to softness in the data
storage market.
    Lukas Winkler, president and chief executive officer, commented,
"The timing of government orders in our Environmental Health and
Safety business has always been difficult to predict. We still expect
to receive these orders in the near future, and we are quite confident
about the long-term growth potential of this market. We remain
committed to strengthening our focus on our company's core
competencies to continue to drive our strategy of profitable growth
for INFICON."

    Presentation of Third Quarter Results

    INFICON will report the company's final third quarter results and
fourth quarter outlook on Thursday, October 21, 2004 at 7:00 a.m.
CET/1:00 a.m. EDT. A conference call has been scheduled for 4:00 p.m.
CET/10:00 a.m. EDT that same day and can be accessed by dialing
+1.706.634.1033 at least 10 minutes prior to the call. A live webcast
of the conference call will also be available in the Investor
Relations section of the INFICON website, www.inficon.com.
    A telephone replay of the call will be available from 7:00 p.m.
CET/1:00 p.m. EDT on October 21 through 5:59 a.m. October 29 CET/11:59
p.m. EDT on October 28. To access the replay, please dial
+1.800.642.1687 (international callers dial +1.706.645.9291),
conference ID #1203046. An archived replay of the conference webcast
also will be available on the INFICON Web site.

    ABOUT INFICON

    INFICON is a leading developer, manufacturer and supplier of
innovative vacuum instrumentation, critical sensor technologies, and
advanced process control software for the semiconductor and
vacuum-coating industries and other industrial applications. This
analysis, measurement and control products are vital to original
equipment manufacturers (OEMs) and end-users in the complex
manufacturing of semiconductors, flat panel displays, magnetic and
optical storage media and precision optics. INFICON also provides
essential instrumentation for gas leak detection and toxic chemical
analysis to the air conditioning/refrigeration, emergency response and
industrial hygiene markets. Headquartered in Syracuse, New York,
INFICON has world-class manufacturing facilities in the United States
and Europe and worldwide offices in the U.S., China, France, Germany,
Japan, Korea, Liechtenstein, Singapore, Switzerland, Taiwan, and the
United Kingdom. For more information about INFICON and its products,
please visit the Company's website at www.inficon.com.



    This press release and oral statements or other written statements
made, or to be made, by us contain forward-looking statements that do
not relate solely to historical or current facts. Forward looking
statements can be identified by the use of words such as "may",
"believe", "will", "expect", "project", "assume", "estimate",
"anticipate", "plan", "continue", "resumes", "opportunity,"
"potential", "outlook", "forecast" or "guidance." These
forward-looking statements address, among other things, our strategic
objectives, trends in vacuum technology and in the industries that
employ vacuum instrumentation, such as the semiconductor and related
industries and the anticipated effects of these trends on our
business. These forward-looking statements are based on the current
plans and expectations of our management and are subject to a number
of uncertainties and risks that could significantly affect our current
plans and expectations, as well as future results of operations and
financial condition. Some of these risks and uncertainties are
discussed in the Company's Annual Report on Form 20-F for fiscal 2003
and the Company's reports on Form 6-K filed with the Securities and
Exchange Commission during 2004. As a consequence, our current and
anticipated plans and our future prospects, results of operations and
financial condition may differ from those expressed in any
forward-looking statements made by or on behalf of our company. We
undertake no obligation to publicly update or revise any
forward-looking statements, whether as a result of new information,
future events or otherwise.

    CONTACT: INFICON
             Betty Ann Kram, 315-434-1122
             BettyAnn.Kram@inficon.com
             or
             sensus pr GmbH
             Europe:
             Bernhard Schweizer, +41-43-366-5511
             bschweizer@sensus.ch
             or
             Lippert/Heilshorn & Associates, Inc.
             North America:
             Jody Burfening/Harriet Fried
             212-838-3777
             jbs@lhai.com