PURPOSE: To shorten the distance from an objective lens to a fixed section in a spring-supported type objective lens driving device so as to house the device in the window frame of an optical disk cartridge.

CONSTITUTION: An objective lens 1 is held at the central part of a three- dimensional mobile body 2 along the direction of tacks and the mobile body 2 is supported at four points by means of four plate springs 3a-3d for focusing which are arranged in parallel with each other. The end sections of the springs 3a-3d on the opposite side to the mobile body 2 are connected to a fixed supporting section 6 by using one plate spring 5 for tracking. The spring 5 is arranged in parallel with the direction of tracks at the central part of a repeating plate 4 and both ends of the spring 5 are connected to the section 6.