A fixing apparatus includes a heating member (6); a temperature detecting member (4) for detecting the temperature of the heating member (6); a power supply controller for controlling the power supply to the heating member (6) so that the temperature detected by the temperature detecting element (4) during a fixing operation is maintained substantially constant at a predetermined fixing temperature; and temperature selecting means for selecting a fixing temperature in response to both the temperature or the heating member before beginning of the fixing temperature control and a rate of the temperature change of the heating member upon supplying a predetermined amount of power to the heating member or upon turning it off. <IMAGE>
