A thermal transfer printer according to the present invention includes; a head mounting base with a thermal head attached thereto, and disposed so as to oppose a platen roller, a locomotion board including a supporting system for supporting the head mounting base so as to be spaced apart from and approaching to the platen roller, and being movable in an extending direction of the thermal head, a slider provided in connection with the supporting system, and being movable in the extending direction of the thermal head, wherein the head mounting base is spaced apart from and approaching to the platen roller by the supporting system as the slider moves.