A tape cassette includes a pair of cassette halves and a pair of hubs enclosed between the cassette halves, and about which a recording medium, or tape can be wound. Each cassette half includes a first molded body and a second molded body overlying it. The first molded body has a first principal surface and a first upstanding wall which is perpendicular to the principal surface and forms an integral part thereof and a part of a peripheral surface of the half. The second molded body has a second principal surface which is generally rectangular and overlies the first principal surface, and a second upstanding wall connected to the first upstanding wall to form the peripheral surface of the half therewith, forming an integral part of the second principal surface and surrounding it. The first and second upstanding walls are connected by a junction having a thickness increasing gradually across the thickness of the half.