A new and simplified method of fabricating anodic aluminum oxide has been developed. This new method uses anodization but follows a route different from the commonly known 1-or 2-step anodization. General-purity (99.7%) commercial aluminum is used instead of the high-purity aluminum required in conventional anodization. The disordered arrangements of pores that initially form on the surface of aluminum rearranged by self-diffusion inside the anodic aluminum oxide (AAO) layer via long-term heat treatment. The enlargement of the pores on AAO that crystallized to phase was achieved by pore widening. Uniformly distributed nanopores with a diameter of 75 nm and wall a thickness of 16 nm were formed on a 9 mm thick AAO film. These ordered nanochannels were obtained over an area of several square millimeters, with a density of 1:4 Â 10 10 pores per cm 2 .