A method for investigating permittivity within a target domain comprises a step of measuring, for a plurality of pairs of contact element groups, the contact elements of the contact element groups being arranged in capacitance measurement connection with the target domain, an electrical quantity of interest proportional to the capacitance of a capacitor formed by a pair of contact element groups; the contact elements comprising a plurality of electrodes supported between the target domain and an electrically conductive background body limiting the capacitance measurement zone of the electrodes. The contact elements may further comprise the electrically conductive background body.