An image forming apparatus includes a tray configured to accommodate a plurality of sheets which are conveyed out of the tray for printing, a pressing member movable between a first position at which the pressing member presses the plurality of sheets against the tray and second position at which the pressing member does not press the plurality of sheets against the tray, a drive mechanism configured to cause the pressing member to be moved between the first and second positions, and a control unit configured to control the drive mechanism to move the pressing member into the first position, while a sheet is not supplied for printing from the tray and into the second position while the sheet is supplied for printing from the tray.