PURPOSE: To enable the use of a low-cost and thin ink ribbon to contrive a long-life ribbon cassette, by providing a polymeric material resistant layer having a given resistivity and a conductive layer on a print circuit portion with no cover of a protective film.

CONSTITUTION: A print head is provided with a base 1 serving as a substrate of the print head, a flexible print circuit base material 2 formed on the base 1, a print circuit 3 formed on the base material 2, and a protective film 4. Furthermore, a polymeric material resistant layer 5 having a given resistivity is bonded on an exposed portion of the print circuit 3 and thereon a conductive layer 6 formed by vapor deposition or metal plating treatment is bonded. In this manner, by using a system wherein an electric current flowing in the print circuit 3 passes through the resistant layer 5 to the conductive layer 6 and finally to the ground, the portion of the resistant layer 5 generates heat to provide the function of the print head.