The invention relates to a window lifter (2) comprising at least one lifting rail (20) for fixing and lifting or lowering a window pane (9) and at least one gliding element (40, 43) which is guided in the lifting rail (20) and is displaced by a lifting arm (21, 22) of the window lifter (2) associated with the gliding element (40, 43). The aim of the invention is to provide a window lifter which enables a window pane to be mounted in a particularly fast and simple manner. Said aim can be achieved in such a manner that detachable and/or openable fixing means (50), maintaining the gliding element (40, 43) in a predetermined position until the fixing means (50) are detached and/or opened.