PURPOSE: To materialize an electrode foil for an electrolytic capacitor whose capacitance is stable immediately after manufacture by constituting a metallic film out of the aggregate of column structure, and oxidizing this metallic film in plasma.

CONSTITUTION: A metallic film includes titanium or metal selected from Mg, Ca, Sr, Ba, and Al, and is constituted of the aggregate of column structure. This column is made on the surface of a substrate so that the enlargement ratio may be 30 to 1000 times within the range of 5×1o8-1×1012 pieces/cm2 in density and 5-1000 in interval. And, the deposition of the metallic film and the glow discharge are performed continuously inside the same vacuum vessel. Hereby, it has an effect of lessening the aging change of capacitance and stabilizing the capacitance of a cathode foil for an electrolytic capacitor sharply. Furthermore, it is excellent in the productivity.