A device for the detection of a medically active implant capable of electrical stimulation that is located within an individual and comprises - at least two electrodes that can be brought into electrical contact with the individual, - an electrical voltage measuring unit, which is electrically connected to the at least two electrodes and is able to produce electrical voltage time signals, - an evaluation unit that is connected to the electrical voltage measuring unit and comprises the following components: - a unit for determining a power spectral density based on the electrical voltage time signals measured between the at least two electrodes, - a unit for determining local maxima within the power spectral density and the so-called peak frequency respectively assigned to them, - a unit for determining the lowest common denominator of at least one part of the determined peak frequencies, - a comparator unit, which on the basis of the lowest common denominator, which corresponds to a stimulation frequency (f) of the medically active implant, and information stored in a reference database, carries out a data comparison and generates a comparator result, as well as - a signal unit which is in communication with the comparator unit and produces a signal as a function of the comparison result. - at least two electrodes that can be brought into electrical contact with the individual, - an electrical voltage measuring unit, which is electrically connected to the at least two electrodes and is able to produce electrical voltage time signals, - an evaluation unit that is connected to the electrical voltage measuring unit and comprises the following components: - a unit for determining a power spectral density based on the electrical voltage time signals measured between the at least two electrodes, - a unit for determining local maxima within the power spectral density and the so-called peak frequency respectively assigned to them, - a unit for determining the lowest common denominator of at least one part of the determined peak frequencies, - a comparator unit, which on the basis of the lowest common denominator, which corresponds to a stimulation frequency (f) of the medically active implant, and information stored in a reference database, carries out a data comparison and generates a comparator result, as well as - a signal unit which is in communication with the comparator unit and produces a signal as a function of the comparison result. - a unit for determining a power spectral density based on the electrical voltage time signals measured between the at least two electrodes, - a unit for determining local maxima within the power spectral density and the so-called peak frequency respectively assigned to them, - a unit for determining the lowest common denominator of at least one part of the determined peak frequencies, - a comparator unit, which on the basis of the lowest common denominator, which corresponds to a stimulation frequency (f) of the medically active implant, and information stored in a reference database, carries out a data comparison and generates a comparator result, as well as - a signal unit which is in communication with the comparator unit and produces a signal as a function of the comparison result.