Antitheft alarm system for a car having a car stereo

摘要

An alarm device is provided in a car. A criminal act such as braking of a window of the car is detected and a criminal act signal is produced. In accordance with the criminal act signal, the alarm device is operated. When an ignition switch of the car is operated by an ignition key within a first predetermined time after opening of a door of the car, the production of the criminal act signal is stopped.