To certainly separate an ink sheet 21 in an ink sheet cartridge 20 and a recording paper 4 after printing.

A cartridge main body 30 of an ink sheet cartridge 20 is formed in a rectangular frame-like shape in a plan view with a pair of right and left side plates 31a, 31b, an upper cover piece 27 for interlocking the sheet supply side upper part, and a partition plate 21 for interlocking the sheet taking up side upper part. A thermal head 22 and a printing part of a platen 17 are made to face in the frame. The conveyance route for a printed recording paper 4 is provided between the upper surface of the partition plate 21 providing a lower chute part, and a rib-like upper chute part 27 projecting on the lower surface of an upper cover member 6 disposed thereabove.