A disk driver in which a disk is inserted has a head (12), a holder (5), and a slider (14). The holder ascends and descends between a first position and a second position. The head ascends and descends between a third position and a fourth position in response to the ascending and descending of the holder. The disk (3) is inserted into or ejected from the holder (5) at the first position when the head (12) is at the third position, and information is recorded on or reproduced therefrom by the head at the fourth position when the holder is at the second position. Since the third position is higher than the first position so that the head does not hit the inserted disk, there is a space between the first and third positions. Accordingly, the slider (14) is located in the space so that it can avoid hitting the head, and thus the disk driver can be made thin.