A thermal protector includes, in a fixed manner, a first terminal and a second terminal that are respectively connected to external circuits, at lower left/right ends of the longitudinal directions of a base, and a right end at which a movable plate and a bimetal are superimposed is fixed to the right end of the upper surface of the base and is connected to the second terminal. A fixed contact is fixed to an internal end of the first terminal that is exposed in the left end of the base. A movable contact is fixed at a position facing the fixed contact on the lower surface of the left end of the movable plate. A partition wall that encloses the movable contact and the fixed contact from three directions is provided and bent plate planes are formed on both sides of the movable plate in the vicinity of the movable contact. The bent plate planes adjust the flow direction of hot air in cooperation with the partition wall so as to prevent a malfunction of a breaking arc flying to surrounding conductive members.