PURPOSE: To miniaturize a printer by making a thermal head movable between the left and right end parts of a cartridge and eliminating a useless space caused by protrusion of the cartridge.

CONSTITUTION: The title printer is constituted of a thermal head 1 and a cartridge 2 and the thermal head 1 performs heat transfer printing while it presses an ink ribbon 3 for heat transfer to a medium 4 and the cartridge 2 contains the ink ribbon 3. In this case, the thermal head 1 is constituted in such a way that it mainly moves in the right and left directions with the cartridge 2 when printing and starting a new line is performed and it secondarily moves in the right and left directions in parallel to the ink ribbon 3 between the left end part and the right end part of the cartridge.