Abstract: A window regulator for moving a window glass up or down so as to open or close a window of an automotive vehicle door having two guide rails substantially vertically disposed and horizontally spaced in parallel with each other and two sliding members secured to the window glass and mounted on the two guide rails, respectively, for sliding movement. One of the two sliding members is vertically spaced above the other of the two sliding members and caused to slidingly move up or down along the guide rail, thereby moving the window glass up or down so as to close or open the window of the automotive vehicle door.