Unit for driving of objective

Disclosed is an objective actuator comprising an object lens holder for holding an object lens, the object lens holder being mounted on a support shaft in a manner that the object lens holder is slidable along and rotatable about the support shaft; a drive coil mounted on the object lens holder; first yoke provided with drive magnets, the first yoke being mounted in such manner that the drive magnets confront with the drive coil, the first yoke having a center hole which is larger in diameter than the support shaft, the first yoke and the support shaft are integrally connected by molding; and shaft holding member defined by filling a resin at the center hole of the first yoke, the shaft holding member including a base portion.