PURPOSE: To prevent reverse driving and to prevent recording paper from shifting from a specific position by using a stepping motor and a worm wheel speed reducing mechanism for the recording paper conveying mechanism.

CONSTITUTION: The recording paper conveying mechanism has the worm wheel speed reducing mechanism, which consists of a worm 50 coupled with the rotary shaft of the stepping motor 34 and a worm wheel 52 engaged with the worm 50. A roller 54 is coupled with the rotary shaft of the worm wheel 52. The roller 54 is provided nearby a recording head 18 and recording paper 42 which is supplied from a supply roll 56 is conveyed toward the recording head 18. Thus, the worm wheel 52 is not driven reversely with an external force, so the thermosensitive recording paper 42 is not drawn to have no position shift. Therefore, the position of the thermosensitive recording paper can accurately be held.