To provide an induction heat fixing device using, as an electromagnetic induction heat generative member, a member having Curie point higher than a fixing temperature, fixing device being designed such that a means for detecting a predetermined voltage or current is provided in order to detect temperature higher than a preset temperature and supply of power to a fixing unit is stopped, and to provide an image forming apparatus.

A fixing sleeve 10 is made of a magnetic material having Curie point higher than the fixing temperature. The means for detecting the voltage or current of an excitation coil 104 is provided. A safety circuit detects from the waveform of the detected voltage or current that the temperature has exceeded the preset temperature, and stops supply of power to the fixing unit.