To provide an image forming apparatus which hardly causes such a failure that peeling of paper from a plate cylinder is unstable to cause a curling-up phenomenon.

A stencil printing apparatus includes a compressed air generating means (20-26) discharging compressed air to the leading edge of the paper (27) pressed on an outer circumferential surface of the rotating plate cylinder (1), and a control means (28) controlling the compressed air generating means (20-26) such that discharge pressure of the compressed air may be constant regardless of printing speed. The compressed air generating means (20-26) is connected to a peeling pawl (14) through a hose (14a) in Fig.1.