PURPOSE: To conduct cleaning of attached ink and prevent contamination of a printer body as well by parallely disposing a washer liquid feed roller and a washer liquid absorbing roller to conduct cleaning of the periphery of a film with ends and a thermal head when the film is traveling.

CONSTITUTION: When a washer liquid suction port protruding in a thrust direction on one side of an ink cartridge 7 engages a washer liquid feed port protruding from a part of an ink jet printer body 1, washer liquid is fed into a washer liquid feed roller 9. Simultaneously with the start of printing, a film with ends 8 moves, so that the washer liquid feed roller is caused to rotate by friction, whereby ink attached to the surface of the film is scraped off without causing wear thereon. And by means of a washer liquid absorbing roller 10 disposed at a position facing the roller 9, liquid in excess after cleaning is prevented from falling into the ink jet printer body, enabling thereby stable printing to be achieved.