PURPOSE: To provide an Al alloy foil material for electrolytic capacitor electrode having a high surface area expansion ratio by etching treatment.

CONSTITUTION: This Al alloy foil material for electrolytic capacitor electrode is composed of a heat-treated material of Al alloy foil material having a composition consisting of 2-20ppm of one or ≥2 elements among Pb, Bi, In, and Sn and the balance Al with inevitable impurities. This heat-treated material has a concentration gradient where the content of the above-mentioned surface area enlarging components in the outermost surface part is regulated to be 0.25-3wt.% and the content in this outermost surface area is gradually decreased through the region from this part to the position at a prescribed depth within 0.5-20μm from the surface and also the content is decreased to ≤10ppm, equal to the content in the central part of the foil material. By this method, the electrolytic capacitor can be miniaturized and made highly efficient.