Stapler (1) which in the course of a reciprocating working stroke (V) staples a workpiece (4), preferably a sheaf of papers, which stapler is powered by an electric motor which, via a transmission arrangement (5) drives the stapler during the working stroke, whereby the motor is activated and initiates the working stroke from a certain starting region as a result of the workpiece moving a trigger (32,33) which forms part of a trigger device (6) to a position at which a circuit-breaker (7), which forms part of the same electrical circuit (8) as the motor is connected to, is closed by the trigger, and whereby a release arrangement (9) connected to, and operatively acted upon, by a rotating means (11) which forms part of the transmission arrangement moves the trigger during the return phase of the working stroke to a non-closing position at which the circuit-breaker returns to an open position, thereby breaking the electric circuit and deactivating the motor, with the result that the working stroke ends in the starting region, whereby the trigger (32,33), when it has been moved to close the circuit-breaker (7) and the working stroke has been initiated by the force from a first elastic means (21), remains in the position at which it closes the circuit-breaker.