Abstract: Disclosed is a device for opening/closing an opening element of a motor vehicle by detecting movement of a users limb, the device including an approach and/or contact detection sensor including a single electrode and an analyzer for analyzing the variations in capacitance of the electrode, and an opening element opening/closing control unit. The device also includes: a sealed housing including first and second metal surfaces; and a unit for detecting a predetermined form of the variations of the electrode, exhibiting a succession of a predetermined number of peaks of predetermined amplitude within a predetermined period; the first and second surface being separate, and the electrode being located outside the sealed housing, in such a way that the electrode is coupled electrically to the at least one first surface and to the at least one second surface so as to create at least two approach and/or contact detection areas.