PURPOSE: To obtain the satisfactory characteristics with use of copper and also to decrease the number of production processes of a dielectric resonator, by forming the 2nd copper film having the thickness double as much as the skin depth after formation of the 1st copper film on the ceramics.

CONSTITUTION: The 1st copper film is formed on the dielectric ceramics for high frequency by the electroless plating process. Then an electrolytic luster plating process is carried out with use of a copper sulfate solution for formation of the 2nd copper film having the thickness double as much as the skin depth. Thus the uniformity, denseness and smoothness of those copper films are im proved together with the satisfactory Q characteristics. Furthermore the variance is reduced between the electrical conductivity of an electrode and the Q characteristics with improved density and intensity of the electrode. The produc tion processes can be decreased with use of a copper material.