TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The support forming step comprises molding powder for support comprising binder and pore-forming agent and then sintering by heat-treating, preferably (i) mixing powder comprising nickel metal and/or nickel oxide and yttria-stabilized zirconia (YSZ) with binder, pore-forming agent or mixing powder comprising nickel oxide, cobalt oxide, copper oxide, ferric oxide and/or chromium(III) oxide powder and powder comprising rare-earth or alkali metal oxide-doped zirconia, rare-earth or alkali metal oxide-doped ceria, bismuth oxide, barium strontium cerate compound and/or lanthanum strontium gallium magnesium oxide with binder and pore-forming agent or mixing conductive ceramic powder including perovskite type structured oxide compound of (AB'O3) (I) and powder comprising rare-earth or alkali metal oxide-doped zirconia, rare-earth or alkali metal oxide-doped ceria, bismuth oxide, barium strontium cerate compound and/or lanthanum strontium gallium magnesium oxide with binder and pore-forming agent or mixing conductive ceramic powder including perovskite type structured oxide compound of (A'B'O3) (II) and powder comprising rare-earth or alkali metal oxide-doped zirconia, rare-earth or alkali metal oxide-doped ceria, bismuth oxide, barium strontium cerate compound and/or lanthanum strontium gallium magnesium oxide with binder and pore-forming agent or mixing zirconia based oxide, alumina based oxide, mullite based oxide, silica oxide, carbide and /or nitride with an organic binder, a solvent and a pore-forming agent, (ii) then molding the obtained mixture, and (iii) sintering by heat-treating at 600-1600 degrees C to form porous support, where yttria-stabilized zirconia is zirconia doped with 2-20 mole% yttrium. The mixing weight ratio of nickel metal and/or nickel oxide and YSZ is 3:7-7:3. The mixed composite conductive layer is formed by coating paste or slurry comprising conductive composite powder, solvent and binder on one or both surfaces of the support by slurry coating, impregnating, spray coating, spin coating, screen printing, tape casting and then heat-treating. The coating step is repeatedly performed to adjust the thickness of the mixed composite conducting layer. The method further comprises forming a functional layer (30) constituting anode or cathode, prior to the step of forming the mixed composite conductive layer on one or both sides of the support to solve the problem of difference in coefficient of thermal expansion or sintering shrinkage rate and forming a functional gradient layer or multi-layered functional gradient layer with slight difference in composition of the mixed composite conductor layers and forming catalyst layer (40) constituting anode or cathode on the mixed composite conductor layers,A = La, Sr, Ca, Ba, Sm or Y;B' = Mn, Co, Fe, Cr, Y, Ti, Ni, Cu or Bi; andA' = La, Sr, Ca, Ba, Sm, Y, Pr or Nd.Preferred Components: The support is of flat type and/or tubular type. The conductive powder is mixture of conductive ceramic powder made of (I) or (II) and electrolyte powder comprising rare-earth or alkali metal oxide-doped zirconia, rare-earth or alkali metal oxide-doped ceria, bismuth oxide, barium strontium cerate compound and/or lanthanum strontium gallium magnesium oxide or a mixture containing lanthanum calcium cobalt chromium oxide of formula ((LaxCa1-x)(CoyCr1-y)O3) (LCCC) and YSZ in a weight ratio of 90:10-20:80. The mixing ratio of conductive ceramic powder made of (I) or (II) and electrolyte powder 90:10-10:90. The slurry or past further comprises a sintering aid. The sintering aid is at least one of titanium dioxide, manganese dioxide, strontium carbonate, barium carbonate, calcium carbonate, silicon dioxide, chromium(III) oxide, bismuth oxide, yttrium oxide, ceria, scandium oxide and niobium oxide. The mixed composite conductive layer has thickness of 0.1-900 mu m and sintered density of 70-100%.x, y = 0-1. EXAMPLE - No suitable example given.