PURPOSE: To prevent positional slip of image recording from happening while ensuring high picture quality by using a platen roll with a comparatively low rubber hardness by a method wherein rubber parts are formed of rubber with a low rubber hardness, and a recording paper holding member which presses recording paper to a platen roll side is provided in the vicinity on the upstream side of a heating part of a thermal head.

CONSTITUTION: The rubber hardness of a rubber part 5b of a platen roll 5 is kept at a rubber hardness at a degree in which damage is not given to a heating part 6a of a thermal head 6, and also picture quality deterioration, density unevenness or wrinkles, etc., are not generated, e.g. Hs 45-55. The leading end of a recording paper is pinched by a recording clamp mechanism 13, and the recording paper is wound on the surface of the platen roll 5 and rotated. When the recording paper passes by a spring baffle 24 position, the recording paper is planarly pressed to the surface of the platen roll 5, extending to the total width. Therefore, the rear end of the recording paper is being kept pressed by the spring baffle 24 to the vicinity of the heating part 6a of the thermal head 6. By this method, the recording paper does not separate from the platen roll 5.