Provided is a method of manufacturing a solid electrolytic capacitor, including the steps of: forming a capacitor element including an anode body having a dielectric coating film on a surface thereof; impregnating the capacitor element with a polymerization liquid containing a precursor monomer of a conductive polymer and an oxidant; impregnating the capacitor element impregnated with the polymerization liquid with a silane compound or a silane compound containing solution; and forming a conductive polymer layer by polymerizing the precursor monomer after impregnating the capacitor element with the silane compound or the silane compound containing solution.