A control unit adjusts spacing between a head with a heater and a storage medium of a storage unit by controlling power of the heater. The control unit measures first values of touchdown heater power at a first temperature set as temperature condition. And the control unit estimates second values of the touchdown heater power at a temperature other than the first temperature set on the measurement of the first values, on basis of a conversion equation. And the control unit determines heater power setting values to adjust the spacing between the head and the storage medium, for each of the sub-areas, on the basis of the first values and the second values.