PURPOSE: To stabilize attracting and holding force by installing a permanent magnet in the way both ends of the magnet are projected toward both ends of an armature more than both leg pieces of an iron core as to bring both ends of the armature into contact with the magnet.

CONSTITUTION: The upper face 3d of both end parts 3b, 3c of a permanent magnet 3 is installed in the way the upper face 3d is projected toward the both ends 4b, 4c of an armature 4 from the tip faces 1d, 1e of both leg pieces 1b, 1c of an iron core 1. When electricity is applied to a coil 2, the one piece 1b of the iron core 1 and the other piece 1c are excited to N-pole and S-pole, respectively. Consequently, since the center part 4a of the armature 4 is supported by the center part 3a which is magnetized by S-pole of the magnet 3, the end part 4b is attracted by the piece 1b and the end parts 4c is repelled by the piece 1c and swings on the part 4a as a fulcrum. At that time, the face 3d of the part 3b of the magnet 3 is in projected state toward the face ld of the piece 1b of the core 1 and thus the part 4b of the armature 4 is brought into contact with the face 3d of the part 3b. As a result, attracting and holding force is increased and stabilized.