Solid electrolytic capacitor and a method for manufacturing the same

According to the present invention, a solid electrolytic capacitor is manufactured by repeating a plurality of times a first step of immersing a substrate made of a valve metal whose surface is roughened and which is formed with an insulating oxide film in an ethylene dioxythiophene solution and a second step of bringing the substrate into contact with an oxidizing agent solution containing quadrivalent cerium salt at a concentration of 1% to 7% by weight so that the cumulative total time during which the second step is performed is shorter than five minutes, thereby forming a solid high molecular polymer electrolyte layer on the surface of the substrate. According to the present invention, it is possible to form a solid high molecular polymer electrolyte layer comprising polyethylene dioxythiophene under a normal temperature and in a short time without damaging a valve metal substrate constituting an electrode and produce a solid electrolytic capacitor whose leakage current is low.