A handling apparatus mounted on a moving member for holding, conveying, and installing a workpiece has a floating plate attached for radial movement to an apparatus body 10 connecting with the movable member, and a workpiece holding device for holding the workpiece on the floating plate. A lock plate is provided for fastening the floating plate to the apparatus body in a radial direction, A fastening piston is coupled to the lock plate through a fastening rod, and the floating plate can be fastened at any position. An aligning piston on which a tapered surface is formed is mounted on the apparatus body for reciprocation. The tapered surface of the aligning piston engages an aligning hole of the floating plate to return the floating plate in the radial direction to an origin position.