PURPOSE: To contrive to improve the operability of an image forming device by a method wherein printing direction is automatically set on the basis of fed image data.

CONSTITUTION: A CPU 81 stores image data for one page sent from a host device 2 in page buffer 83a so as to expand the image data into bit map data to be supplied from IC cards 95 in order to store the expanded bit image data in an image data buffer 83b. The CPU 81 counts the number of characters for one column of the bit image data stored in the image data buffer 83b so as to be judge the printing direction by the counted value in order to point the printing direction to an engine controlling circuit 5 through an internal bus 92 and an engine interface 91. The engine controlling circuit 5 drives a cassette feeding solenoid 7a by the driving circuit 6 of mechanism part in response to the pointing of the printing direction by the CPU 81 or drives a cassette feeding solenoid 7b so as to deliver paper in order to form image on the paper.