A relay lens driving device provided in an optical head moves a relay lens in the direction of an optical axis thereof to correct a spherical aberration that may be caused by an error in the thickness of a cover layer of an optical disk. The relay lens driving mechanism has a lens to correct spherical aberrations, a lens holder which holds the lens, a first parallel plate spring which supports the lens holder at one end thereof, an intermediate member attached to the other end of the first parallel plate spring, a second parallel plate spring arranged to extend from the intermediate member to the lens holder to support the intermediate member at one end thereof, and a fixing member which fixes the other end of the second parallel plate spring.