A multilayered glass-ceramic substrate using copper as wiring material is fabricated by a step of forming wiring patterns with Au paste for connection of semiconductor chip prepared by adding at least one of Ni powder, Pt powder and Pd powder to Au powder, and copper oxide paste mainly composed of CuO powder, on a green sheet, and burning out the organic pattern by heat treatment in air, a step of reducing the copper oxide electrode by heat treatment in a reducing atmosphere containing hydrogen, and a step of sintering the substrate material, copper oxide electrode and gold electrode by heat treatment in nitrogen. Since the Au wiring pattern is formed on the top layer of the multilayered substrate in this constitution, wire bonding of high reliability is realized. Besides, by making use of the excellent solderability of Au, it may be also applied in flip-chip mounting of semiconductor. In addition, in this Au paste composition, the melting point of Au may be raised, and alloying or fusing is avoided if sintered at 900.degree. C. together with Cu electrode.