A new technique for studying the surfaces of metals that can be anodically oxidized is proposed. Its development and application for a variety of aluminum surfaces is described. It gives a measure of the specific area of aluminum with what may be described as a continuously variable resolution from 40Aå to 1000Aå. The results agree with measurements of specific surface area by a radiochemical technique which has a resolution of about 20Aå and optical measurements made at resolution greater than 1000Aå. The shape of a particular surface area vs. resolution curve gives information about the topography of the surface.