The fixing device includes a pair of rotating bodies which conveys a
recording medium between a nip; a heating unit which heats at least one
of the rotating bodies; and a temperature detection unit which detects a
temperature of at least one of the rotating bodies. The temperature
detection unit detects a temperature change until an image forming
apparatus is normally operated since the heating unit starts the heating,
and the temperature change is stored. It is judged that the image forming
apparatus is in an abnormal state when the temperature detection unit
detects a temperature change different from the temperature change in the
normal operation. A temperature control unit stops passage of current
through the heating unit when it is judged that the image forming
apparatus is in the abnormal state.