Manufacturing method of electrolytic capacitor

A method of manufacturing an electrolytic capacitor, comprising:

• forming a capacitor element by winding an anode foil and a cathode foil in a manner that a separator is interposed therebetween, the anode foil having a dielectric oxide film thereon, the cathode foil being subjected to a treatment enlarging surface area;
• immersing the capacitor element in a fluid dispersion containing conductive polymer fine particles dispersed therein;
• depressurizing the capacitor element and drying the capacitor element, after the immersing the capacitor element in the fluid dispersion so that the conductive polymer fine particles adhere to surfaces of fibers of the separator, fill between the fibers of the separator, and adhere to surfaces of the anode foil and the cathode foil in a manner that the adhesion and filling of the conductive polymer fine particles are such that an amount of the fine particles decreases from ends toward a center of the capacitor element;
• impregnating the capacitor element with an electrolytic solution after the adhesion and filling of the conductive polymer fine particles;
• placing the capacitor element in a bottomed, metallic case;
• and
• sealing an opening of the metallic case with a sealing member.