Exhibit 99.1

      AMIS Holdings Accelerates Vesting on Certain Stock Options

    POCATELLO, Idaho--(BUSINESS WIRE)--Dec. 7, 2005--AMIS Holdings,
Inc. (NASDAQ:AMIS), parent company of AMI Semiconductor, a designer
and manufacturer of state-of-the-art integrated mixed-signal products
and structured digital products for the automotive, medical and
industrial sectors, today announced that its Board of Directors has
accelerated the vesting of certain unvested and "out-of-the-money"
stock options previously awarded to employees and officers that have
exercise prices per share of $13.00 or higher. As a result, options to
purchase approximately 1.9 million shares of AMIS stock became
exercisable immediately.
    Options held by non-employee directors are excluded from this
vesting acceleration. In addition, in order to prevent unintended
personal benefits to executive officers, restrictions will be imposed
on any shares received through the exercise of accelerated options
held by those individuals. Those restrictions will prevent the sale of
any shares received from the exercise of an accelerated option prior
to the earlier of the original vesting date of the option or the
individual's termination of employment.
    The accelerated options have exercise prices per share ranging
from $13.00 to $20.00, with a weighted average exercise price per
share of $15.18, and represent approximately 24 percent of the total
of all outstanding AMIS stock options. Based on the closing price of
$10.13 for shares of AMIS common stock on the NASDAQ National Market
on December 2, 2005, the date of the Board of Directors' approval, the
accelerated options had no incentive or economic value at the time of
acceleration.
    "Accelerating the vesting on these "out-of-the-money" options will
reduce future compensation expense required by new accounting
regulations that will take effect in the first quarter of 2006,
without negatively impacting employee retention," stated Christine
King, president and CEO. Under the recently issued Financial
Accounting Standards Board Statement No. 123R, "Share-Based Payment,"
AMIS will apply the expense recognition provisions relating to stock
options beginning in the first quarter of 2006. As a result of the
acceleration, AMIS expects to reduce the pre-tax stock option expense
it otherwise would be required to record by approximately $5.0 million
in 2006, $2.7 million in 2007, and $0.9 million in the aggregate for
2008 and 2009.

    About AMI Semiconductor

    AMI Semiconductor (AMIS) is a leader in the design and manufacture
of silicon solutions for the real world. As a widely recognized
innovator in state-of-the-art integrated mixed-signal products and
structured digital products, AMIS is committed to providing customers
with the optimal value, quickest time-to-market semiconductor
solutions. Offering unparalleled manufacturing flexibility and
dedication to customer service, AMI Semiconductor operates globally
with headquarters in Pocatello, Idaho, European corporate offices in
Oudenaarde, Belgium, and a network of sales and design centers located
in the key markets of the United States, Europe and the Asia Pacific
region.



    CONTACT: AMIS Holdings Inc., Pocatello
             Investor Relations:
             Wade Olsen, 208-234-6045
             wade_olsen@amis.com
             or
             Media Relations:
             Tamera Drake, 208-234-6890
             tamera_drake@amis.com