A device and method are provided for starting the engine of a motor vehicle equipped with an authentification device, which includes an access entitlement unit that the user can carry and a vehicle-side access entitlement test device having a receptacle for the access entitlement unit, and with a tripping unit, which includes a tripping element that when activated can initiate an engine start. The tripping element and the receptacle are connected mechanically together such that the tripping element is actuatable by an essentially translatory movement of the access entitlement unit inserted into the receptacle.