Abstract: A solid non-polar capacitor having excellent electrical characteristics such as high capacitance, which includes an electrode formed from a conductor having a porous surface, a dielectric layer formed from an insulating polymer thin film on the porous surface of the conductor, and a counter electrode formed from an electrically conductive layer on the surface of the dielectric layer. Preferably, the electrically conductive layer constituting the counter electrode consists of an electrically conductive polymer film prepared by chemical oxidation polymerization and an electrically conductive polymer layer prepared by electrolytic polymerization.