An anode includes a base body of a sintered porous material of niobium particles, a surface layer made of crystalline niobium oxide formed on the base body, and an anode lead having partly buried in base body 1a. A dielectric layer containing amorphous niobium oxide is formed by anodic oxidation on the cathode. An electrolyte layer made of polypyrrole is formed on the dielectric layer and a cathode is formed on the electrolyte layer. A conductive adhesive layer and cathode terminal are formed on an upper surface of the cathode. The anode lead exposed from the base body is connected to an anode terminal by welding. In addition, a mold resin is formed to cover the second conductive layer, the cathode terminal and the anode terminal so as to expose cathode terminal and an end of anode terminal.