Proximity sensor for determining the proximity to an electrically conductive body having the following features: a) a transmission arrangement for transmitting an alternating magnetic field at a selected frequency (33, 80a-80n) in order to generate eddy currents in a conductive body, b) a reception arrangement for detecting an alternating magnetic field generated inter alia by the eddy currents, c) a detection means for detecting one or more frequencies of the detected alternating magnetic field, said frequencies lying outside of a predefined frequency range having the selected frequency (33, 80a-80n) and having an amplitude value above a predefined threshold value and having d) a control logic having: i) a blocking circuit for determining frequencies of a predefined further frequency range having the frequency detected by the detection means or a plurality of predefined further frequency ranges having in each case at least one of the frequencies detected by the detection means as frequencies blocked for a predefined period, ii) a selection controller for determining a repetition frequency (35, 80a-80n) of the respective selected frequency, said repetition frequency following the respective selected frequency (33, 80a-80n) and differing from the respective selected and from the blocked frequencies, and iii) a time controller for the continual selection of the respective repetition frequency of a presently selected frequency (33, 80a-80n) as the new selected frequency (33, 80a-80n) temporally directly after or temporally delayed after a time window predetermined for the presently selected frequency (33, 80a-80n). a) a transmission arrangement for transmitting an alternating magnetic field at a selected frequency (33, 80a-80n) in order to generate eddy currents in a conductive body, b) a reception arrangement for detecting an alternating magnetic field generated inter alia by the eddy currents, c) a detection means for detecting one or more frequencies of the detected alternating magnetic field, said frequencies lying outside of a predefined frequency range having the selected frequency (33, 80a-80n) and having an amplitude value above a predefined threshold value and having d) a control logic having: i) a blocking circuit for determining frequencies of a predefined further frequency range having the frequency detected by the detection means or a plurality of predefined further frequency ranges having in each case at least one of the frequencies detected by the detection means as frequencies blocked for a predefined period, ii) a selection controller for determining a repetition frequency (35, 80a-80n) of the respective selected frequency, said repetition frequency following the respective selected frequency (33, 80a-80n) and differing from the respective selected and from the blocked frequencies, and iii) a time controller for the continual selection of the respective repetition frequency of a presently selected frequency (33, 80a-80n) as the new selected frequency (33, 80a-80n) temporally directly after or temporally delayed after a time window predetermined for the presently selected frequency (33, 80a-80n). i) a blocking circuit for determining frequencies of a predefined further frequency range having the frequency detected by the detection means or a plurality of predefined further frequency ranges having in each case at least one of the frequencies detected by the detection means as frequencies blocked for a predefined period, ii) a selection controller for determining a repetition frequency (35, 80a-80n) of the respective selected frequency, said repetition frequency following the respective selected frequency (33, 80a-80n) and differing from the respective selected and from the blocked frequencies, and iii) a time controller for the continual selection of the respective repetition frequency of a presently selected frequency (33, 80a-80n) as the new selected frequency (33, 80a-80n) temporally directly after or temporally delayed after a time window predetermined for the presently selected frequency (33, 80a-80n).