An optical pickup comprises an objective-lens driving device including a movable section provided with an objective lens, a focusing coil, and tracking coils, and a fixed section provided with a single magnetic circuit having a magnetic gap, the focusing coil and the tracking coils being disposed in the magnetic gap. The point of application of a tracking-driving force, the point of application of a result force of focusing-driving forces occurring in and outside the magnetic gap, and the position of the center of gravity of the movable section are made to substantially coincide with each other. In addition, the objective lens and the magnetic circuit are disposed within an area of a window in a lower shell of a optical disk. Further, a through hole for accommodating a lower portion of a yoke of the magnetic circuit is provided in a mounting base on which the objective-lens driving device is mounted. An inclining fulcrum and a height adjusting means for inclining the objective-lens driving device about the inclining fulcrum are provided in the vicinities of the through hole.