A difference value between a gain control value when a head comes into contact with a recording medium and a gain control value when the head floats with respect to the recording medium by a target floating amount is stored in advance. When the information access device is actually operated, supply power to a heater is adjusted to once bring the head into contact with the recording medium, a first gain control value adjusted by a gain control section when the head comes into contact with the recording medium is obtained, a second gain control value to be adjusted by the gain control section when the head floats from the recording medium by the target floating amount is obtained from the first gain control value and the difference value, and the supply power to the heater is adjusted such that the second gain control value is supplied to a gain variable amplifier by the gain control section.