PURPOSE: To attempt an increase in the driving force of a reciprocating drive type electromagnetic output unit and the improvement of the responsiveness by arranging a magnetic substance having an exciting coil between both projections magnetized the same pole by a permanent magnet.

CONSTITUTION: Circumferential projected walls 5a, 5b provided at the opposite ends of a cylindrical case 1 are magnetized the same pole by a permanent magnet 6. A plunger 8 having load driving pieces 20 and an exciting coil 7 are arranged to freely slide between both circumferential projected walls. Therefore, when the plunger 8 is excited, attractive force and repulsive force act to the opposite ends respectively in the same direction. So the plunger 8 is driven by the resultant force and the driving force becomes strong and no differ ence in the driving force exists at the time of reciprocation as well. Furthermore, the electromagnetic force caused by the permanent magnet 6 and the current of the coil 7 acts with the resultant force in the same direction. Therefore, stronger driving force is available. As the driving pieces 20 are provided at the opposite end sections of the plunger 8, plunger inertia becomes small and the responsiveness will further be improved.