Within a case (4), are accommodated an electromagnet (8) having a fixed core (8c) and a movable core (8d) capable of contacting and separating from the fixed core (8c); a movable contact point support (7a) which moves in parallel with the movable core; a return spring (7b) which causes the movable contact point support to return to an initial position; and a driving lever (9) which rotates with a rotation support point portion (9a) provided on one end thereof as a support point, and which transmits attraction movement and release movement of the movable core to the movable contact point support. The rotation support point portion of the driving lever is fitted into and supported by a support point recess (5a) provided in an inner face of an extinction cover (5) mounted on the case.