Apparatus and method for position control of optical system, and storage and reproduction apparatus

A position control apparatus of an optical system capable of positioning a lens at a high accuracy in a near-field optical system using a solid immersion lens. An objective lens 2 and a solid immersion lens are fixed to a lens holder 4. The lens holder 4 is moved by a tracking actuator 5 in the tracking direction of an optical disk 51 and is moved by a focus actuator 8 in the focus direction. The focus actuator 8 is controlled on the basis of the electrostatic capacitance occurring between the solid immersion lens 3 and the optical disk 51.