The invention concerns a device for detecting the presence of a user to allow and/or prevent access inside a motor vehicle, the vehicle comprising at least a decorative element fixed to the body (2) proximate to an opening (O), the device comprising at least an electrode detecting (1) the presence of a user and a processing circuit (5) connected to the detecting electrode. The invention is characterised in that the decorative element (ED) has at least an electrically conductive part (12) coupled at least partly with the detecting electrode (1) so as to form an active detecting surface.