Provided is a fixing device including: a heater; a heating body that is heated by the heater and is caused to rotate; a pressure body that is in contact with the heating body, and is caused to rotate; a plurality of temperature sensor units each including a temperature sensing element that is covered with a protective member and is in contact with the heating body in order to sense a temperature of the heating body; and a control unit that recognizes temperatures of the heating body at respective portions thereof based on signals received from the temperature sensor units, brings the heater into an ON state if the recognized temperatures exhibit a temperature difference of a predetermined value or larger, judges that the protective member has peeled off if all the temperatures sensed by using the temperature sensor units are recognized to have risen, and corrects the temperature.