A thermal transfer printer has a platen and a thermal head between which are pinched a transfer paper sheet and an ink film, so that the ink is transferred from the ink film to the transfer paper sheet as heat is applied to the transfer paper sheet by the thermal head. The film is supplied by a supply roll and is taken-up by a take-up roll. The thermal head is swingable between a position where it contracts the platen and a position away from the platen. When the thermal head is in the position away from the platen, the distance therebetween is greater than the maximum diameter of the supply roll. A film drum can hold a plurality of films each being constituted by the supply roll and the take-up roll. Swing arms are provided for demounting the supply roll of a selected film from the film drum and for bringing the same to a position away from the film drum, and also for returning the same from this position to the film drum. During the movement of the supply roll between the position in the film drum and the position away from this position, the thermal head is moved away from the platen so as not to hinder the movement of the supply roll.
