A toner image on a photosensitive drum exposed with an LED light beam radiated from an LED section and developed by an image-forming unit is transferred by an image-forming apparatus to a printing paper when the printing paper, which is fed from a paper feed tray or a manual feed tray and which is transported by a transport mechanism by a feeder section, passes through a process section. A control unit of the image-forming apparatus determines an exposure timing at which the LED section starts the exposure, depending on a supply source of the printing paper sheet to be subjected to the transfer by the process section. Therefore, the error of the photosensitive member arrival time, which is caused by the change of the transport route, is absorbed, and the deviation of the transfer start position, which results from the error, is suppressed.