In a solid electrolytic capacitor having an electrolyte layer consisting of a solid electrolyte layer and a liquid, the solid electrolytic capacitor, which suppresses a dedoping reaction and which ESR thereof does not keenly increase, in particular, after a loading of heat stress, is provided. In the solid electrolytic capacitor, the electrolyte layer is formed in the capacitor element which is formed by opposing an anode foil and a cathode foil. This electrolyte layer includes the solid electrolyte layer and the liquid. The solid electrolyte layer includes a conductive polymer consisting of a dopant and a conjugated polymer. The liquid is filled in air gaps in the capacitor element on which the solid electrolyte layer is formed. The electrolyte layer includes ammonia as a cation component, and a molecular ratio of the cation component relative to 1 mol of a functional group which can contribute to a doping reaction of the dopant, in the electrolyte layer is 23 or less.