PURPOSE: To enable reduction of the number of components and also to facilitate the assemblage by making one of cassette guides provided with both functions of a motor holder and a cam supporting shaft.

CONSTITUTION: In the tape disk, the right cassette holder 2 is provided with the horizontal motor holder part 2a and the cam supporting shaft part 2b vertical to the lower surface of motor holder part 2a as one body. So, the right cassette guide 2 is made to have the function to hold a motor 22 and the function to support a disk cam 68, thereby the number of components is reduced. Also, the assemblage is facilitated since the right cassette guide 2 can be fixed by a screw 65 after a shaft hole 69 of the disk cam 68 is engaged with a small diameter part of the cam supporting shaft part 2b and the shaft part 70 of disk cam 68 is engaged with a hole 71 of a deck chassis 1.