PURPOSE: To obtain a high reliable tape cassette capable of performing a reliable braking operation even when an elastic brake pawl made of a resin is deformed by heat and stress.

CONSTITUTION: The tape cassette is provided with guides 17 and 18 for separating the restraining pawls 10 and 11 to be engaged with ratchets 5 and 6 from the outer circumferences of hubs 5 and 6 in accordance with a brake releasing operation. Moreover, the cassette is provided with a guide 20 for engaging the restraining pawls 10 and 11 with the ratchets 5 and 6 and guiding the restraining pawls 10 and 11 approximately along the outer circumferences of the hubs 3 and 4 in accordance with the braking operation. By this constitution, there is no fear of impairing the braking operation due to deformation.