PURPOSE: To reduce the number of components and to enhance working efficiency at the time of manufacturing and attaching by having a first temperature detecting element and a second temperature detecting element integrally constituted.

CONSTITUTION: A leaf spring 11 is fixed at one end of a temperature fuse 5 (first temperature detecting element) in a state where it is electrically connected and a thermistor 2(second temperature detecting element) is attached to a substrate 20. Since the thermistor 2 is integrally attached to the leaf spring 15 where the temperature fuse 5 is fixed in a temperature detecting body 100, the thermistor 2 and the temperature fuse 5 are simultaneously pressed to the surface of a heat. fixing roller by the spring force of the leaf springs 11 and 15 when the temperature detecting body 100 is attached at a specified position on the heat fixing roller. Also the thermistor 2 fixed at the leaf spring 15 is fixed with the substrate 20, so that the number of components is reduced and man-hour at the time of the manufacturing is reduced.