An aluminum electrolytic capacitor includes: an exterior case of a bottomed cylindrical shape for accommodating a capacitor element in which an anode foil and a cathode foil are wound in an overlapping manner with a separator interposed therebetween; and an elastic sealing member for sealing an opening of the exterior case, wherein the exterior case is formed with, on an outer circumferential surface, a plurality of tapered concave portions whose depth in the radial direction becomes shallow from the bottomed cylindrical bottom toward the opening side, whereby a tapered raised portion, which is raised toward the center side in the radial direction, is formed on an inner circumferential surface located on the back surface of the concave portion, and the capacitor element is abutted and supported by the raised portion.