There is provided a disk drive including a base chassis, a first optical pickup mechanism including a disk rotation drive disposed on the base chassis, first optical pickup unit to write and/or read data to and/or from a first optical disk and a first pickup moving mechanism to move the first optical pickup unit radially of the first optical disk, a second optical pickup mechanism disposed opposite to the first optical pickup mechanism and including a second optical pickup unit to write and/or read data to and/or from a second optical disk and a second pickup moving mechanism to move the second optical pickup unit radially of the second optical disk, and a controlling means for detecting the movement of one of the optical pickup units and moving the other optical pickup unit to make weight balancing of the base chassis. Thus, the base chassis weight is balanced while one of the two optical pickup units is being moved.