PURPOSE: To avoid swell due to plating and to attain excellence in the economy by forming a chemical plating Ni-P being a background electrode as a specific film and applying thick plating by means of chemical Cu plating.

CONSTITUTION: The surface of a dielectric resonator ceramics 2 is processed in the order of degreasing, chemical etching, susceptibility and activation, a film 4 is formed for a background electrode whose thickness is 0.1μm or over and less than 1/10 of the skin depth by the chemical Ni-P plating, and thick plating is implemented as a layer 5 by chemical Cu plating to form double electrode layers. After the chemical etching processing is implemented in this way, when the chemical Ni-P plating 4 is implemented as the background plating, since the Ni-P in the etching trace is grown from the initial deposition in a minute film form, the close adhesion on the border of the dielectric substance raw Ni-P film is very excellent. The swell due to plating is avoided by forming the Cu film on the Ni-P film face by the chemical Cu plating.