A device for confirming the operation of an electromagnetic actuator which comprises a fixed core, a moving core detachably opposed to said fixed core to form a closed magnetic path together with the fixed core, and an electric winding wound around the closed magnetic path. The device is for detecting the displacement of the moving core relative to the fixed core, wherein the point of time at which the displacement of the moving core due to a direct current flowing through the electric winding is finished is detected using transient variations of the waveform of the direct current. Having a simple structure, the device is small in size and weight, low in cost, and highly reliable in confirming the operation of the actuator.