Abstract: Multiple terminal capacitor consisting of two opposite electrode plates, at least one thereof being sub-divided into a plurality of sub-electrodes separated from each other by small gaps, said sub-electrodes each forming with an area of the opposite electrode plate an individual sub-capacitor of the plate-capacitor or cross-capacitor type, said sub-capacitors being connected to circuitry such that any individual sub-electrode of a sub-divided electrode plate together with its related electrode area of the opposite electrode plate constitutes with the surrounding sub-electrodes and their related opposite electrode areas a sub-capacitor system of the Kelvin Guard-ring capacitor type, and such that the cooperation of at least two of the sub-capacitor space systems allows the measurement of any deviation in the plan-parallelity between two surfaces or in the angular coincidence with an accuracy of 1:10.sup.6 or better.