The invention relates to a method for functionalising the surfaces of adhesive closing parts which form, with correspondingly formed adhesive closing parts, an adhesive closure that can be repeatedly opened and closed. The surface energy of the adhesive closing part is modified by means of a proton and/or electron exchanging medium, especially in the form of donors or collectors, using high energy in such a way that the physicochemical properties of the material of the adhesive closing part can be adjusted without a coating and with ageing resistance, by the attachment of functional groups ofthe exchanging medium to the adhesive closing part material. The invention also relates to a device for carrying out one such method.