PURPOSE: To provide a cassette cart equipped with a brake mechanism capable of being released by an external release mechanism, which can prevent a fault from being caused by worker's brake operation and which can remarkably improve workability of transporting a belt-like rubber material by the cassette cart and productivity of tires.

CONSTITUTION: During transport by a cassette cart on which a belt-like rubber material W is loaded, brake mechanisms 10a, 10b are automatically operated to fix the rotations of an unwinding shaft 4 and a winding shaft 6. Further, in the case where the cassette cart is set to a drive means, the locked condition of the brake mechanisms 10a, 10b is released by a brake release mechanism 26 so that the unwinding shaft 4 and the winding shaft 6 become freely rotatable.