Provided is a wire driving device including: wires one ends of which are attached to a movable member; pulleys to which the other ends of the individual wires are secured; driven gears that are coaxially secured to the individual pulleys; a drive gear that is connected to a driving source; and movable gears that are disposed between the drive gear and the individual driven gears and that can transmit the motive power of the driving source to the driven gears from the drive gear. The movable gears are provided in a movable manner so that the movable gears engage with the drive gear and the driven gears when the drive gear is rotated in a direction, and so that the engagements of the movable gears with at least one of the drive gear and the driven gears are released when the drive gear is rotated in the other direction.