PURPOSE: To provide a disk device for enabling an independent access to a recording surface which is divided into a plurality of regions and for achieving a plurality of independent recording media when observed from an upper device.

CONSTITUTION: A disk device where a recording track is formed in eddy shape or concentrically on the recording surface of a circular disk for recording information is provided. Then, the recording surface of a disk 1 is divided into a recording/reproduction region 11 at the inner-periphery side and a recording/ reproduction region 12 at the outer-periphery side and recording/reproduction heads 21 and 22, head control parts 31 and 32. intermediate interfaces 41 and 42, upper interface control parts 51 and 52, upper interfaces 61 and 62. and upper devices 71 and 72 are connected in this order at the regions 11 and 12. Then. a first control group consisting of a recording/reproduction head 21 and a second control group consisting of a recording/reproduction head 22 can operate independently.