Magnetic disk device

The invention provides a magnetic disk device capable of appropriately setting a system area. First setting information and second setting information are stored in a memory of a magnetic disk device. The first setting information indicates a second track, among a plurality of first tracks included in the magnetic disk, which is set to be not used on the basis of the defect inspection. The second setting information indicates a third track selected from one or more first tracks different from the second track. When the access destination is the user area, the controller converts the logical address information to the physical address information while sliding the second track and the third track. When the access destination is a system area, the controller converts the logical address information to the physical address information while causing all of the first tracks other than the third track among the plurality of first tracks to slide over. 本发明提供能够适当地设定系统区域的磁盘装置。在磁盘装置具有的存储器中保存有第1设定信息和第2设定信息。第1设定信息表示第2磁道，