To provide a thermo-protector capable of stably holding a fusible material by properly eliminating creep deformation and allowing a case to be simply formed of a plate stamping member, in the case type thermo-protector operated by releasing, by melting the fusible material, the elastic distortion energy of an elastic body held by joint fixation by the fusible material.

A protector body A is so structured that both ends of the plate-like or linear elastic body 2 bent by a longitudinal compression force are fixed to one-side conductor 12 out of a pair of vertically separated conductors 11 and 12; at least one-side fixation thereof is carried out at a flexural angle 0 through the fusible material 3 and elastic distortion energy is kept in the elastic body 2; and a contacting part between a bending intermediate part of the elastic body 2 and the other side conductor 12 is used as a contact part p. The protector body is housed in a protective case 4 composed by fixing plates 41 and 42 to the upper and lower surfaces of a plate frame 40.