The present invention provides an electrode arrangement 10, 10′ for an ion trap, ion filter, an ion guide, a reaction cell or an ion analyser. The electrode arrangement 10, 10′ comprises an RF electrode 12a, 12b, 12a′, 12b′ mechanically coupled to a dielectric material 11. The RF electrode 12a, 12b, 12a′, 12b′ is mechanically coupled to the dielectric material 11 by a plurality of separators 13 that are spaced apart and configured to define a gap between the RF electrode 12a, 12b, 12a′, 12b′ and the dielectric material 11. Each of the plurality of separators 13 comprises a projecting portion 13b and the dielectric material 11 comprises corresponding receiving portions 11a such that on coupling of the RF electrode 12a, 12b, 12a′, 12b′ to the dielectric material 11, the projecting portion 13b of each separator 13 is received within the corresponding receiving portion 11a of the dielectric material 11. The present invention also relates to an ion trap comprises the electrode arrangement 10, 10′ and a method of manufacturing the electrode arrangement 10, 10′.