A cleaning roller and a platen roller are provided in a first rotating plate which rotates around a main shaft. The cleaning roller and the platen roller are disposed at an equal distance from the main shaft. In printing, the platen roller is positioned at a facing position to face the thermal head. In cleaning the thermal head, the rotating plate rotates to retract the platen roller from the facing position, and then the cleaning roller is positioned at the facing position in place of the platen roller. The foreign matters on the thermal head are scraped off by rotating the cleaning roller in a state that the cleaning roller is contacted with the thermal head.