Abstract: The instant invention relates to a power screwdriver with torque limiter, with a drive unit and a secondary transmission, with an output shaft for the attachment of a keyed bit. According to the invention the drive unit is a pneumatic motor (2) with a compressed-air intake (13) and a compressed-air outlet (14), whereby the differential pressure between the compressed-air intake (13) and the compressed-air outlet (14) (measuring circuits 19 and 20) is taken as the measure of the torque produced by the power screwdriver (1). The differential pressure is measured in a differential pressure measuring device (21) and the measure signal is transmitted to a control unit (23). The control unit (23) contains a comparator unit which compares the measured differential pressure signal with a set value of differential pressure (adjusting potentiometer 24) and transmits a switching signal to a switch unit (solenoid valve 19) to switch off the power screwdriver when the compared values become equal.