Abstract: In a printer having a pen movable in an X-direction, a platen, and a sheet feeder for feeding a recording sheet in a Y-direction and displaced from the platen in the Y-direction, the platen comprises a platen roller rotatable around a center axis thereof. A pen is opposite to the platen with the recording sheet interposed therebetween and is brought into contact with the recording sheet to press the recording sheet against the platen roller, each time when recording is carried out. The platen roller is rotated by frictional force which occurs between the recording sheet and the platen roller. The platen roller may forcibly be rotated in the same direction as a driving roller included in the sheet feeder. Preferably, the driving roller has a knurling portion along an outer peripheral surface.