The present invention provides a highly reliable disk apparatus which is reduced in size, thickness and weight, and which can surely prevent the double insertion of disk-shaped recording media with a simple structure to thereby prevent a contact between each of the disk-shaped recording media. In the disk apparatus of the present invention, a disk guide is rotatably held in the proximity of an opening for inserting and ejecting a disk-shaped recording medium, which is formed in the stationary frame fixed to the casing, and the disk guide leads the disk-shaped recording medium to the inserting and ejecting operations and also closes at least a part of the above opening.