To provide a printing medium formed of an ink ribbon and a heat-sensitive paper laminated over each other, with a capability to print data with high printing quality without creases generated in the ink ribbon during printing.

An ink layer 3C of an ink ribbon 3G and a faint sticky layer 3D of a recording material 3H which shows faint adhesive strength under normal pressure, are pressure-welded under a specified high pressure. Thus both layers 3C and 3D become stuck to each other over their entire surfaces. The fusion temperature of the ink layer 3C is set higher than the color developing temperature of a heat-sensitive color developing layer 3E, and therefore, the part, where data are printed by heat at not less than the color developing temperature and at less than the fusion temperature, of the heat-sensitive color developing layer 3E of the recording material 3H, develops a color. Further, when the ink ribbon 3G is released from the recording material 3H, data are printed in color by heat due to the residual ink layer 3C remaining on the base film 3B side. In addition, the part, where data are printed by heat at higher than the fusion temperature, of the recording material 3H, is constituted in the way that the heat-sensitive transfer printing is performed, i.e. the transfer of the ink layer 3C to the recording material 3H side, when the ink ribbon 3G is released from the recording material 3H.