To provide a safe protector of a battery for entirely blocking an electrical connection with respect to the battery at abnormality times.

The protector has a thermosensitive element 2, operated in response to a temperature and switching a conduction state between a first terminal 12a and a second terminal 12b provided in a body, and a resistive element 5 for carrying a current and heating the thermosensitive element 2, when the thermosensitive element 2 operates. The body is provided with a third terminal 13a for carrying a current to the resistive element 5. The thermosensitive element 2 switches a fixed contact 11 for carrying a current to the second terminal 12b, accompanying its operation and a working contact 13 for carrying a current to the third terminal 13a via the resistive element 5.