A plurality of passenger protecting devices, such as airbags or seatbelt pretensioners, are actuated by a controller upon detection of a collision. According to types of collision, particular passenger protecting devices are selected and actuated. The controller includes a main circuit and a safeguard circuit for actuating the passenger protecting devices, and the selected passenger protecting devices are actuated when both circuits generate signals for actuating the passenger protecting device. The passenger protecting devices to be selected according to types of collision are pre-programmed in the main circuit and automatically transmitted to the safeguard circuit.