To prevent the print quality from lowering by performing complementary printing efficiently through other sound print element when a part of print element in a print head is missed.

A detecting/storing program 2a of missed print element and a complementary printing program 2b are provided in a control section 1. Numbers of print element being used for complementing one or a plurality of numbers of missed print element are previously arranged in matrix on a table 2d corresponding to defective pin in order to perform complementary printing of missed print dot efficiently. When a pin is missed, a key switch 5a is operated while viewing the display on the LCD 5b at an input section 5 and the missed pin is inputted and stored in a memory 2e before starting the detecting/storing program 2a. Alternatively, a missed pin can be detected automatically by executing test print pin by pin and scanning the print results by means of the optical scanner 3d in a print mechanism 3.