PURPOSE: To stably feed paper by making the conveying direction of a laminate set changeable freely in the direction opposite from the conveying direction in the stage of an ordinary fixing process and providing a supply part for the laminate set before the passage to a fixing device and a take-out part after the passage thereof.

CONSTITUTION: A feed roller 18 is provided in the position of a paper discharge tray 12 near the fixing device 10 and can be driven forward and backward together with paired rollers constituting the fixing device 10. A laminated paper discharge passage 20 is formed upward from the conveyor belt 8 side of the fixing device 10 and the tray-shaped laminate set take-out part 22 is provided to the front end thereof. The tray 12 is commonly used as the supply part for the laminate set. At least the feed roller 18 and the paired roller of the fixing device 10 are rotated backward so that the laminate set L is subjected to a lamination treatment in the stage of passing the fixing device 10 and is discharged onto the take-out part 22 when the laminate set is inserted from the supply part of the laminate set in common use as the tray 12 in the lamination mode.