To improve working efficiency of mounting a thermal fuse and a heat radiation plate on a base plate by fixing a position of the thermal fuse to the base plate and enabling a lead to be easily inserted into a hole.

The thermal fuse 1 has leads 6 to be inserted into holes 5 formed on a base board 4. The heat radiation plate 2 made of metal, has legs 8 to be inserted into mounting holes 7 formed for mounting it on the base plate 4, and a half-punch 9 (protrusion) for contacting one side face of the thermal fuse 1. A clip 3 has an energizing part 11 making the half-punch 9a (protrusion) contact with one side face of the thermal fuse 1 by energizing it. The position of the thermal fuse 1 to the heat radiation plate 2 is fixed by making it contact the half-punch 9a (protrusion) by an energizing part 11. The leads 6 can be easily inserted into the holes 5 by fixing the position of the thermal fuse 1.