A porous body of Ti-Al alloy has a novel structure for a solid electrolytic capacitor, having improved values of leakage current and dielectric loss. The porous body of Ti-Al alloy has spherical particles which partially contact each other to form an integral body. The surfaces of the spherical particles have a ruggedness in the order of several microns or less. Because the diameter of the spherical particle is greater than the size of the ruggedness, the porous body has rough voids which provide a wide passageway through which a manganese nitrate solution penetrates. The wide passageway is effective for decreasing the number of times when there is a thermal decomposition of the manganese nitrate, thereby reducing the series resistance of the resultant cathode. In addition, this novel structure makes it possible to avoid production difficulties which are usually encountered when a solid electrolytic capacitor, having a high capacitance, is produced from a finely divided Ti-Al alloy.