To accomplish resistance welding by applying a current, whose level is similar to what is applied to the case where Ni-or Fe-containing alloy is used as the leadframe base material, to this solid-state electrolytic capacitor which is constructed by forming a dielectric coating layer, a solid-state electrolytic layer, and a negative electrode leadout layer, successively on the surface of a positive electrode made of a valve-action metal, by resistance-welding a positive electrode leadframe made of Cu or an alloy composed mainly of Cu to a positive electrode lead wire planted in the end face of the positive electrode, and by connecting the negative electrode leadframe to the negative electrode leadout layer.

A coating film composed of a material, whose specific resistance is higher than that of the leadframe base material, is formed at the junction between the positive electrode leadframe and the positive electrode lead wire.