A calibration method for inertial drive actuator of driving a target moving body among a plurality of moving bodies to move by inertia between a first movement limit position and a second movement limit position in relation to an oscillating plate that is moved to reciprocate by a moving member, and detecting positions of the moving bodies based on electrostatic capacitances includes detecting electrostatic capacitances of opposing parts of a moving body side electrode provided in a target moving body and an oscillating plate electrode provided in the oscillating plate is detected at the first movement limit position and the second movement limit position, respectively; and calculating a ratio of a difference between the electrostatic capacitances at the first movement limit position and the second movement limit position to a movement limit distance that is a distance between the first movement limit position and the second movement limit position. At least one of the first movement limit position and the second movement limit position is a position where the target moving body abuts against a non-target moving body.