PURPOSE: To send correctly recording paper without generating stepping-out on a motor carrying the recording paper even if the recoding paper having a different size is used.

CONSTITUTION: A device inserting and taking off a low frictional member 14 in accordance with a size of using recording paper 11 is provided between a thermal head 12 and platen roller 13. In the case where recording paper having a A4 size is used in a device where the recording paper having, for example, the maximum B4 size is usable, since the low frictional member 14 is inserted into a sphere D where the head 12 and platen roller 13 are contacted directly with each other, a load of a motor can be reduced. Then a device changing rigidity of a platen roller in accordance with the size of the recording paper or that changing a distribution of pressing force to the platen roller of the head may be provided between the head and platen roller and an end part of the platen roller may be made into a low frictional part.