A step portion is formed on a lower casing of a process cartridge, and a film member composed of flexible resin film is fixed to a step portion such that a front portion can bend. The film member guides a sheet to a photosensitive drum. In this manner, a thin sheet which lacks firmness is adhered on an upstream side of a transfer position in a rotational direction of the photosensitive drum, thus preventing electrical discharges, while a thick sheet which has firmness is bent by the front portion of the film member in a direction in which a leading edge of the sheet is headed, thus guiding the sheet such that operating abnormalities are prevented and an appearance of ghosts is prevented.