An access control device for a motor vehicle and a method for setting the sensitivity of an access control device, include a plurality of ferrite antennas disposed in a door handle of the motor vehicle. The individual ferrite antennas are inclined with respect to one another and with respect to the door surface. Consequently, a widely fanned magnetic field is produced within which a request signal can readily be received by a portable encoder. In order to ensure that interference signals have only little effect on the reception of a request signal, the reception sensitivity of the encoder is increased only after a very powerful advance signal has been received.