PURPOSE: To attain miniaturization, high speed, and high quality by operating printing in each line area from the same direction, storing print data in each line area when a printing operation is not performed, selecting the data to be printed from among the print data, and operating printing.

CONSTITUTION: A carriage 32 is moved to a main scanning direction to recording sheet 40, printing is operated in each line area from the same direction, and it is restored to a printing start enabling position. Then, when the printing operation is not performed by a process part 33, the print data in each line area to be transferred are stored, the data to be printed are selected, and printing is operated. This processing is operated to one line area, and then to the entire line areas of the recording sheet 40. Thus, the capacity of the storage area can be made small, and the width of an image carrier can be made narrow compared with a case that the print data of the entire recording sheet are stored. Moreover, the high speed can be attained by transmitting the print data in each line area.