PURPOSE: To easily discriminate the kind of a film by providing the roll holding member engaged with the engaging parts formed to the end parts of two rotary shafts having a film wound therearound to connect and fix the rotary shafts and providing a kind discrimination means to the roll holding member.

CONSTITUTION: An ink film cassette used in a thermal printer has case members 5, 6 and an ink film is transferred from the supply roll received in the case members to a taking-up roll. Groove like engaging parts 2b, 3b are formed to both ends of the rotary shafts 2a, 3a of the respective rolls and both rolls are supported in a freely rotatable manner within the case members 5, 6 through the coupling members 4a, 4b attached to the engaging parts 2b, 3b. The ink film 1 is supplied to a user in such a state that a roll holding member 7 having a kind display means 8 attached thereto is engaged with the engaging parts 2b, 3b and the case members 5, 6 are fixed and held by the holding member 7 incorporated in the cassette.