An ink ribbon cassette includes first and second rotatable bodies that rotate with an ink ribbon held between the rotatable bodies in sandwiched relation. The second rotatable body includes a hole through which a shaft extends such that the second rotatable body is rotatably supported on the shaft. The shaft may have a circumferential surface conical toward the free end, and the hole may be a conical hole into which the conical shaft extends. The shaft may include a plurality of cylindrical shaft portions that are in line with one another and that have different diameters. The second rotatable body is formed with a plurality of cylindrical hole portions having different diameters corresponding to the cylindrical shaft portions such that the second rotatable body is rotatably supported on the shaft.