<p>An image-forming machine comprising a main body (2) and a process unit (8) adapted to be detachably mounted on the main body (2). The process unit (8) includes a first unit comprising a developing device (18) and a charging corona discharger (16) and a second unit comprising a rotating drum (12) and a cleaning device (22). The developing device (18) comprises a magnetic brush mechanism comprised of a hollow cylindrical sleeve and a permanent magnet disposed within the sleeve and a blade adapted to be brought into press contact with the surface of the sleeve and to decrease sufficiently the thickness of the developer layer on the sleeve surface. The cleaning device (22) includes an elastic blade adapted to be brought into press contact with a photosensitive member disposed on the surface of the rotating drum (12). The toner removed from the surface of the photosensitive member by the action of the elastic blade is recovered into an interior space of the rotating drum (12).</p>