Since both a driving means for lifting a work and a driving means for turning operation must have been arranged in a conventional work transfer apparatus, the apparatus has been large in size and heavy in weight. A work transfer apparatus is provided with a holding tool for holding a window, i.e., the work, and a supporting arm for movably supporting the holding tool. The window held by the holding tool is transferred by a supporting arm to window frames to which the window is to be assembled, and the posture of the window is changed to that corresponds to the window frames. Furthermore, the supporting arm is configured to be a closed loop link mechanism wherein a plurality of links are connected to form a closed loop. The posture of the holding tool one link of a pair of links connected to the holding tool of the supporting arm can be fixed.