Abstract: The tape cassette comprising a hub, an engagement cavity recessed on the outer periphery of the hub, and a clamper fitted into the engagement cavity, wherein the base end part of a tape is engaged between the engagement cavity and the clamper, and the tape is wound around the hub, characterized in that opposite inner upper edges of the engagement cavity each have first end portions and opposite side edges on a tape winding surface of the clamper each have second end portions facing the first end portions, and each of gaps between the first end portions and the second end portions is dimensioned to be about 0.02 mm to about 0.10 mm.

Abstract: A tape cassette of the present invention comprises an upper half and a lower half constituting a cassette body which rotatably contains a hub with a tape wound thereon, a slider disposed in such a manner as to cover the lower half for movement forward and backward, and a spring disposed to a front end portion of the lower half in order to urge the slider forward, a pair of retaining elements each having a projection formed on an outer side thereof being integrally connected to the lower half, the projections being engaged in a pair of first holes or a pair of second holes formed in front and rear portions of the slider to retain the slider urged by the spring, so that a pair of opening portions formed in the lower half can be opened and closed by a pair of opening portions formed in the slider, the height l.sub.1 of a perpendicular surface of each of the projections on the connecting side of the retaining elements being higher than the height l.sub.