A magnetic disk apparatus that uses a head to write data in a plurality of unit areas arranged in an adjacent relationship to each other on a surface of a magnetic disk, and includes: a first recording section that records, in a RAM, the position of a unit area which is a target of data write; a first counting section that counts the number of times of data write operation performed for the unit area corresponding to the position recorded by the first recording section; and a second recording section that records, in a non-volatile storage medium different from the RAM, the side position which is the position of a unit area adjacent to the unit area whose number of records counted by the first counting section is more than a predetermined value.