A capacitor structure and a manufacturing method achieve suppression of ESR increase and improved productivity for electrolytic capacitors produced by a manufacturing process in which an additive layer is applied to a separator before impregnation of a capacitor element. An anode foil and a cathode foil having undergone an area increasing process are laminated and wound via separators, on which additive layers are formed on respective one surfaces, to produce the capacitor element. At least the separator having a surface at the center side of the capacitor element facing the anode foil and a surface at the outer circumference side of the capacitor element facing the cathode foil, has the additive layer formed on the surface at the center side of the capacitor element.