In recent years, in a field of disk drives such as a hard disk drive, data is stored in a magnetic disk with higher density. Along with this, narrower track pitches of the magnetic disk are being used. If off-track in the direction along the track width happens when reading out data from a magnetic disk having a narrow track pitch using a magnetic head, the data written on the track may not be read out correctly. In another case, if off-track in the direction along the track width happens when writing data on a magnetic disk having a narrow track pitch using a magnetic head, the data written on the track may not be read out correctly by the magnetic head.