An optical drive installation device including: a support frame that disposes a removable optical drive to an installation position; a lock mechanism that has a locking member which can move to a locked position preventing the optical drive from being removed or an unlocked position not interfering with the optical drive being removed, and supports the optical drive at the installation position of the support frame when the locking member is set to the locked position; an unlocking mechanism that releases the lock mechanism from the locked position; and a pushing member that pushes the optical drive in the direction in which the optical drive is removed from the installation position.