Window raising device electrically and manually operated, of simple construction and providing for a firm retention of the window in order to obtain a burglar-proof window. A carriage fixed to the window and sliding in a guide is secured to both ends of a flat belt which slides on two return pads made of synthetic material. The belt is perforated or toothed in its portion passing on a toothed drum. The drum is slidingly mounted on a gear of a main sliding shaft which traverses an electrical driving mechanism. The sliding of the main shaft disengages the shaft from the motor drive but does not disengage its gear from the drum in order to provide a manual drive. The device is useable in a door or in a fixed part of a motor vehicle.