PURPOSE: To contrive inprovement and stabilization in quality and efficiency, miniaturization, lightweightedness, degree of serviceability and reduction in cost of production by a method wherein the terminal used for connection of the starting and finishing parts of each coil, the terminal for the change-over switch of each coil and the terminal for commutation circuit are used in common.

CONSTITUTION: A suction coil 23-a with which a relatively strong sucking force can be obtained and a holding coil 23-b having relatively small sucking force which is used to hold a plunger 11-b, which comes in close contact with a fixed core 11-c, are wound around the outer circumference of a bobbin 22, and the starting and ending parts of winding are respectively wound on the terminal 24 which is fixed to the front side face of the bobbin 22. A printed substrate 28, on which a diode 27 will be arranged and fixed in bridge form, is fixed in the gap 26 located between the front side face of the bobbin 22 and the external frame 25, and a terminal 24 is connected to the prescribed position. Besides, a change- over switch 29, with which the suction coil 23-a and the holding coil 23-b will be switched, is fixed to the gap 26 in the constitution of a fixed contact part 29-a and a movable contact point 29-b.