Device for detecting an approach

A device for detecting an approach of a part of a user's body or of a portable user equipment, intended to be housed on board a motor vehicle, including: a near-field communication antenna configured to transmit signals at a high frequency selected between 3 and 30 MHz, the antenna being able to detect the approach of a portable user equipment and to communicate in near-field mode with the portable user equipment. The antenna including at least one winding that extends continuously in the form of a set of comb-shaped rods such that the antenna is able to generate a variation in capacitance in response to the approach of a part of a user's body; a controller for controlling the antenna; and a measurer for measuring a variation in impedance of the antenna, generated by the variation in capacitance.