PURPOSE: To prevent the generation of the impression on the surface of a fixing roller due to a separating pawl, by isolating the separating pawl from the fixing roller up to a prescribed stop position when a supporting plate as a paper ejecting part is set to a fixer.

CONSTITUTION: In this device, a transfer material is prevented from being wound around a rotating fixing roller 4, which has a heater 3 inside, by a separating pawl 6; and when a supporting plate 13 is turned in the direction of an arrow (b) and is set to a fixer 2, an installing plate 29 including the separating pawl 6 is energized clockwise by a spring 32 and is brought into contact with a pin 46 and is pressed downward counterclockwise. Consequently, even when the supporting plate 13 comes near the position of engagement between a pin 26 and a groove 24a, the separating pawl 6 is isolated from the fixing roller 4. When the supporting plate 13 is turned to the main body side furthermore to reach a prescribed set position, a groove 29b of the installing plate 29 and a pin 46 are engated with each other, and the separating pawl 6 is brought into contact with the surface of the fixing roller 4 by the force of the spring 32 without im- pression, and the separating pawl 6 is not damaged.