Electrolytic capacitor and manufacturing method thereof wherein the electrolytic capacitor includes a capacitor element having an anode foil, a cathode foil and a separator, and an electrolyte

An object of the present invention is to provide an electrolytic capacitor using a sintered foil having a metal sintered body at least on its surface as an electrode foil and manufacturing method thereof. The electrolytic capacitor can suppress a deterioration in life characteristics by reducing leakage currents. The electrolytic capacitor 1 of the present invention includes a capacitor element 2 having an anode foil 8 forming a dielectric layer, a cathode foil 9, and a separator 10 arranged between the anode foil 8 and the cathode foil 9; and an electrolyte 3 which is impregnated in the capacitor element 2. The anode foil 8 or the cathode foil 9 are sintered bodies of compositions containing metal powders formed into a foil shape (consisting of a foil-shaped sintered body 8c) or formed into sintered body film 8b composed of the sintered bodies on a surface of a substrate 8a. The electrolyte 3 contains an oxygen-containing acid of phosphorus or a derivative thereof or a salt thereof in a range of 0.01 mass pe