Provided is a solid electrolytic capacitor which retains a high capacitance and a low ESR and has high heat resistance. The solid electrolytic capacitor (10) is obtained by winding a porous anode foil (11) having a dielectric layer formed thereon and a cathode foil (14) together with separators (15) each interposed therebetween, the separators (15) having a solid electrolyte (13) supported thereon. Each layer of the solid electrolyte comprises a conductive composite (a) of a cationized conductive polymer with a polymer anion, a first hydroxy compound (b) having four or more hydroxy groups, and a second hydroxy compound (c) having an amino group and one or more hydroxy groups, the content of the conductive composite (a), in terms of mass proportion, being lower than that of the first hydroxy compound (b) and higher than that of the second hydroxy compound (c).