A vertically movable work platform is suspended and supported by a plurality of suspension wires fed out from one or more of winding rotating bodies which is rotated such that the vertically movable work platform is vertically moved by the rotation of the one or more of winding rotating bodies. A support for receiving and supporting the lowering vertically movable work platform at a work height, and a stopper for preventing the rotation of the winding rotating body in a direction which tends to lower the vertically movable work platform when the vertically movable work platform reaches the work height are provided.