Device having a number of electrode arrangements that can be applied to the surface of the skin of a living animal or human and with which voltages and currents from the skin surface can be obtained, and having a flexible, in particular elastic, retaining element consisting of a flat or film-like moulded part, wherein - the electrode arrangements have a base and a number of pin electrodes standing out from the base in the same direction, - the electrode arrangements are attached to the retaining element, and - the base of the respective electrode arrangement is connected with the retaining element, wherein the pin electrodes of all electrode arrangements stand out in the same direction, - on the respective electrode arrangement, an amplifier arrangement is arranged, and the pin electrodes are connected to the amplifier arrangement, - the amplifier arrangement is arranged on an additional, separate base (15, 15a), that can be removably electrically and mechanically connected with the respective base via click-on connections (16, 19, 19a), and - the retaining element has a number of recesses, and the click-on connections (19, 19a) pass through the recesses of the retaining element, characterised in that, when applied, - the base is in each case arranged on the inside of the retaining element, wherein a connecting part passing through the recess of the retaining element is in each case arranged on the base, - the additional base (15, 15a) is in each case arranged on the outside of the retaining element, wherein the additional base (15, 15a) in each case has an additional connecting part and that side of the additional base (15, 15a) towards which the additional connecting part is directed faces the retaining element, and - the connecting part of the base directly contacts the additional connecting part of the additional base (15, 15a) through the recess of the retaining element, such that the additional connecting part of the additional base (15, 15a) is in electrical and mechanical contact with the connecting part of the base passing through the recess of the retaining element. - the electrode arrangements have a base and a number of pin electrodes standing out from the base in the same direction, - the electrode arrangements are attached to the retaining element, and - the base of the respective electrode arrangement is connected with the retaining element, wherein the pin electrodes of all electrode arrangements stand out in the same direction, - on the respective electrode arrangement, an amplifier arrangement is arranged, and the pin electrodes are connected to the amplifier arrangement, - the amplifier arrangement is arranged on an additional, separate base (15, 15a), that can be removably electrically and mechanically connected with the respective base via click-on connections (16, 19, 19a), and - the retaining element has a number of recesses, and the click-on connections (19, 19a) pass through the recesses of the retaining element, - the base is in each case arranged on the inside of the retaining element, wherein a connecting part passing through the recess of the retaining element is in each case arranged on the base, - the additional base (15, 15a) is in each case arranged on the outside of the retaining element, wherein the additional base (15, 15a) in each case has an additional connecting part and that side of the additional base (15, 15a) towards which the additional connecting part is directed faces the retaining element, and - the connecting part of the base directly contacts the additional connecting part of the additional base (15, 15a) through the recess of the retaining element, such that the additional connecting part of the additional base (15, 15a) is in electrical and mechanical contact with the connecting part of the base passing through the recess of the retaining element.