Abstract: A solid electrolytic capacitor of this invention comprises an electrode provided with an anode lead; a dielectric oxide film, a solid electrolyte layer, a carbon layer, and a cathode layer, which are successively formed on the surface of the electrode; a positive terminal connected to the anode lead; and a negative terminal connected to the cathode layer by means of an electrically conductive adhesive; wherein at least one of the cathode layer and the electrically conductive adhesive comprises a polymer and an electrically conductive powder containing palladium. The capacitor displays little variation in the value of tan .delta. and slight changes in current leakage even when the capacitor is placed under conditions of high temperature and humidity. Moreover, electrical short-circuit failure of the capacitor rarely occurs.