A crash sensor is constructed for triggering a passive safety device, such as an air bag or a seat belt tightening device. The crash sensor is capable to distinguish between different types of impacts such as front impacts, rear impacts, side impacts, and minor impacts, for example occurring in a repair shop. For example, the air bag shall be deployed only in response to a frontal impact. The crash sensor has at leasst two acceleration sensors having sensitivity axes arranged at different angles relative to the longitudinal vehicle axis or travel direction. The output signals of the acceleration sensors are integrated in respective integrated circuits and supplied to a threshold value circuit which in turn provides the necessary signal for activating a trigger circuit. Each signal processing channel is equipped with at least two parallel threshold value switches which cooperate with signal validating or signal recognizing circuits to distinguish between different impacts for permitting the deployment or for preventing the deployment of the safety device. The trigger circuit itself is also a logic circuit in which the individual inputs are received through input conductors carrying signals representing the various criteria for the deployment or prevention of the deployment of the safety device. Thus, the safety device is deployed only if a frontal impact has been recognized.