A fixing apparatus is provided, in which a problem such as the melting of a heater retaining member does not occur when a fixing nip portion performs a fixing processing in a reduced pressure state. In a fixing apparatus of an image forming apparatus capable of feeding a paper by applied pressures of two types or more, the fixing apparatus is changed to a mode in which the applied force is low, and is allowed to perform an operation for cooling the fixing apparatus before starting a current supply to a heater.