Provided is a solid electrolytic capacitor having a lower leakage current than a conventional solid electrolytic capacitor. The solid electrolytic capacitor includes: an anode foil having a surface on which an oxide film is formed; a cathode foil; and a separator disposed between the anode foil and the cathode foil, wherein a solid electrolyte made of a conductive high-molecular weight compound in a fine particle form and a water-soluble high-molecular weight compound solution which is formed of a water-soluble high-molecular weight compound in a liquid form, water and alcohol having a nitro group are introduced into a gap formed between the anode foil and the cathode foil in a state where the water-soluble high-molecular weight compound solution surrounds the solid electrolyte.