A solid electrolytic capacitor using a conductive polymer compound as a solid electrolyte includes an anode body, a dielectric oxide coating formed on a surface of the anode body, a sulfone group-containing silanol derivative layer formed on at least a portion of the dielectric oxide coating by a coupling reaction, and a conductive polymer compound layer formed at least on the sulfone group-containing silanol derivative layer. With this, a solid electrolytic capacitor having a low ESR and a high capacitance and a method of manufacturing the solid electrolytic capacitor can be provided.