An optical-system driving device is achieved that can switch over between objective lenses and is space-saving, lightweight, and simply-configured. An optical-system driving device for recording information onto or playing it back from an optical storage medium, includes a stationary unit having a rotation axis; a movable unit pivotable about the rotation axis; pivotal movement means for pivotally moving the movable unit about the rotation axis; and the movable unit includes a holder having a plurality of optical means that is able to focus a beam of light onto the optical storage medium, and a plurality of conductive elastic members for supporting the holder, wherein an optical axis of each of the plurality of optical means is located substantially equidistant from the rotation axis, and the optical means for focusing the beam of light onto the optical storage medium is selected by pivotally moving the movable unit with the rotation means.