PURPOSE: To make no excessive force to act on an operating point for stabilizing a switching action while for lengthening a contact life by alternately switching an actuation mode of a magnet device from an influential mode to an out-of-influential mode and vice versa by a remote control signal or manual operation.

CONSTITUTION: A contact device 11 is interposed in a load circuit 16 while being provided with a pair of contacts 17 and 17 opening and shutting by a change of magnetization force. A magnet device 12 has a disk-shaped permanent magnet 19 to be arranged near the contact device 11 being provided with nearly cross-shaped driven wings on the upper surface of the permanent magnet 19. The magnet device 12 receives forward force of a driving rod 21 being made to perform a reciprocation by a remote operation part 13 and a manual operation part 15 by a piece of the drive wing 20 to be made to perform intermittent rotation. The magnet device 12 is set up while being alternately switching from an influential mode able to exert magnetization force on the contacts 17 to an out-of-influential mode not able to exert magnetization force on the contacts and vice versa at each stop time of intermittent rotation. In this way, while making no excessive force to act on the contacts, switching operation can be stabilized and a contact command can be lengthened as well.