To present an objective actuator small in the number of parts, easy in soldering and assembling, heightened in the motion precision and brake effect, free from undesired resonance due to torsional motion of the objective lens holding member, heightened in the secondary resonance frequency by the torsional motion of the objective lens holding member, and suppressed of its amplitude. A lens holding member holding an objective lens and a housing are simultaneously and integrally molded through four linear spring members inserted in a die. Afterwards, a pair of magnets are fixed on the lens holding member, and an electromagnetic coil is wound, and wire terminals are wound in the wire arrangement grooves, then a soldered coil frame is fixed on the housing. A brake member is injected into the recess space enclosing linear spring members with the inside of the side wall of the housing and the inner wall, the brake frame, its partition wall, and part of the coil frame, from the side surfaces. The objective lens is mounted on the middle and top of the lens holding member holding the objective lens, and an optical plate is fixed in the middle of the lower surface, thereby forming a rigid nearly hexahedral structure, in which the suspension center by the linear spring members and the driving center by the driving system of the electromagnetic coil and magnets are matched, and the moment balance of the lens holding member including the objective lens and optical plate is achieved on this driving center.