To provide a protector which has little variations in manufacturing and is superior in precision.

The protector comprises a fixed plate 2 having a rising portion 24 and a cut-out portion 22 formed on a welding part 20 and a movable plate 4 having a bent portion positioned at the welding part 20. By engaging the cut-out portion 22 of the fixed plate 2 with the bent portion of the movable plate 4, the positioning precision of the both is improved, and variations in performance of the protector can be suppressed. Furthermore, the rising portion 24 provided in the fixed plate 2 is utilized as a fulcrum at the reversing of a bimetal disk. As a result, displacement amount of a movable contact 6 becomes large and it is prevented that the bimetal disk 3 is reversed, and the contacts becomes rapidly from an open state to a closed state.