PURPOSE: To improve the quality of printing results by providing a line feed control division to control the line feed so that the printing head overscans, and by providing a one-line printing data output position control division to control the position so that printing data overlaps by the overscanning of the printing head.

CONSTITUTION: First one-line printing data cutout division 3 cuts out a first one-line printing data 14 at the dot-number width 13 of the printing head, and printing division 7 (thermal transfer printing system) prints out the data. Hereupon, unless all the printing data 12 are printed out, the cutout division 3 cuts out a next data from the printing data 12. At this time, line feed control division 6 controls the line feed 17 so that the printing head overscans by the width of a common multiple of the printing division's dot pitch and the minimum line feed pitch and controls the cutout position 15 of a second one-line printing data 16 through one-line printing data cutout position control division 4 to a position of overlapping the first printing data 14 by the overscanning of the head.