Abstract: The present invention provides a thermal transfer ink ribbon which has good ink transferability and is capable of producing transferred images which are sharp and have high durability. As the main constituent of a binding material of thermally fusible resin, fine particles of low slipperiness which are not softened at a temperature at which the binding material is softened are contained in an ink layer 13 when the ink layer 13 is deposited to produce a thermal transfer ink ribbon 1. Since the thermally fusible resin is used, the durability of transferred images is high. Because the fine particles are contained, the ink layer can be separated sharply from the thermal transfer ink ribbon 1. As the fine particles are of low slipperiness, no slippage occurs between the thermal transfer ink ribbon 1 and a transfer medium. The fine particles of low slipperiness have an average diameter ranging from 0.3 .mu.m to 3.0 .mu.