To provide a thermoprotector working when elastic deformation energy of an elastic body supported via binding fixation by a fusible material such as solder is released by fusion of the fusible material.

A contact piece 2, in which one lead conductor part 1 between both lead conductor parts 1 and 10 housed on the upper side and the lower side in a housing 6 has elasticity, is fixed in the both end parts while being bent for holding elastic deformation energy, and at least one side fixation 21 is carried out by face binding via the fusible material 3, while the other lead conductor part 10 is brought into contact with the bent contact piece 2. The periphery of the contact part is surrounded by a protection coat. When the fusible material is melted/softened, the elastic deformation energy is released to interrupt electric conduction between the both lead conductors.