An electrolytic capacitor includes a capacitor element and an electrolyte solution impregnated into the capacitor element. The capacitor element includes an anode foil, cathode foil, separator, and a solid electrolytic layer. The anode foil has a dielectric layer on its surface, and the cathode foil confronts the anode foil. The separator is interposed between the anode foil and the cathode foil. The solid electrolytic layer is formed on the surfaces of the anode foil, cathode foil, and separator as an aggregate of fine particles of conductive polymer. The separator has an air-tightness not greater than 2.0 s/100 ml. Sizes of the fine particles measure not greater than 100 nm in diameter, and the fine particles are contained in an amount ranging from 0.3 mg/cm2 to 1.2 mg/cm2 converted to amounts per unit area of the anode foil.