An image forming apparatus includes an apparatus main body to which a cartridge is detachably attached. The apparatus main body includes a frame having an opening portion through which the cartridge is attached to the apparatus main body; an opening and closing member supported by the frame rotatably between an open position in which the opening portion is exposed and a closed position in which the opening portion is covered with the opening and closing member and having a stacking surface on which a sheet is to be stacked; a discharging roller discharging the sheet in a discharging direction onto the stacking surface; and a regulating wall which is movably attached to the opening and closing member and extends from the stacking surface toward the discharging roller in a direction intersecting the discharging direction to regulate an upstream edge of the sheet in the discharging direction.