PURPOSE: To make connection of an electromagnetic contactor and a thermal relay easy even when the mutual pitches of the connection parts are not in harmony.

CONSTITUTION: A connection unit 15 which makes it possible to sufficiently adjust the mutual pitches of a terminal plate 18 in electric power source side for an electromagnetic contactor is composed and when the mutual pitches of the connecting parts of a thermal relay 6 and the electromagnetic contactor are different, the connection unit 15 is connected to the electric power source side of the thermal relay 6. Consequently, without processing the terminal of the thermal relay 6 in electric power source side or connecting a lead wire additionally, the thermal relay 6 can be set in the electromagnetic contactor by one touch.