a magnetic disk, a first area and a second area located on an inner diameter side of the first area being provided therein;

a motor rotating the magnetic disk;

a magnetic head; and

a controller that

receives a write command from a host,

writes, in a case where a first position that is a position designated as a write destination of data by the write command is included in the first area, the data to the first position by the magnetic head while causing the magnetic disk to rotate at a rotational speed of a first value, and

writes, in a case where the first position is included in the second area, the data to the first position by the magnetic head while causing the magnetic disk to rotate at a rotational speed of a second value larger than the first value, wherein

an area, a recording frequency of the magnetic head exceeding a set level in the area, is set as the first area, and

the set level is determined on a basis of an error rate at a time of access.