To improve the reliability of a device by monitoring the rotation start or the rotation stop of a recording medium for management to prevent the rotation start number of times or the rotation stop number of times of the recording medium from exceeding a prescribed value.

Upon start of disk rotation (S1), if the disk rotation start number of times is recorded in a nonvolatile memory (S2), the control unit of the disk device reads the disk rotation start number of times from the nonvolatile memory of the disk device (S3), and adds the number of times "1" to the disk rotation start number of times (S4). If the disk rotation number of times is recorded in the nonvolatile memory (S5), the disk rotation start number of times after the addition of the number of times is written in the nonvolatile memory of the disk device (S6).