BREAKER

PROBLEM TO BE SOLVED: To provide means of precisely and easily attaining expected restoration temperature for a breaker which has components made compact to be applied to a battery pack which is thinner than before.SOLUTION: A movable arm of the breaker has a bent part formed in an intermediate region of the movable part to be pushed up by a thermally-actuated element, and a flat part in a substantially flat plate shape which extends from the bent part to a case. On the flat part, a press contact formed of a projection etc., is further provided between the movable arm and an inner surface of a case of the movable arm to serve as a contact on a bent part side as compared with a contact on a fixed part side which is fixed to the case of the movable arm among contacts between the thermally-actuated element inverted at high temperature and the movable arm, thereby generating contact pressure.