A storage apparatus comprises: a current parameter varying section that can make a write current used for writing information on the storage medium and an overshoot amount corresponding to the write current variable; a detection section that detects an error rate or its corresponding error rate parameter for a plurality of combinations of the write current and overshoot amount varied by the current parameter varying section; a saturation factor calculation section that calculates a saturation factor representing a change in the error rate relative to a unit write current value from the error rate or error rate parameter detected by the detection section; and a current parameter setting section that determines current parameters based on the saturation factor obtained by the saturation factor calculation section for setting.