To provide a heating apparatus which prevents fixing failure by enhancing its responsiveness, and by controlling a decrease in temperature to the utmost at a site where a safety temperature detection element of a heating body is arranged.

This heating apparatus for conducting heat from a heating body 3 through a film includes a circuit connected in series with the heating body 3, a power source 14 and a relay 12. A CPU 10 controls energization from the power source 14 to the heating body 3, and is connected to the relay 12 by way of a relay signal line 17. When a safety temperature detection element 15 detects runaway conditions where a voltage remains impressed on the heating body 3, it stops energization from the power source 14 to the heating body 3. In this case, the safety temperature detection element 15 is provided on the relay signal line 17, and is arranged in the position of the heating body 3. When the safety temperature detection element 15 detects runaway conditions based on the abnormal rise in temperature of the heating body 3, the relay 12 is opened to stop energization of the heating body 3.