To perform an appropriate transfer operation by correcting the transfer displacement of a printing paper sheet with respect to a printer being a printing device, which prints predetermined information on the printing paper sheet, especially, the printer performing a double-sided printing or the like.

In the printer for automatically feeding the printing paper sheet includes: a printing means for printing on the printing paper sheet and transferring it; a leading-end transfer displacement correcting means for correcting transfer displacement when the leading end of the printing paper sheet passes through the printing means; and a control means for carrying out a transfer operation in which the transfer displacement of the leading end is corrected by the correcting means, thereby printing on the optimum printing position in accordance with the corrected transfer operation.