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The scanning tunneling microscope is used to image GaAs pn‐doping superlattices, cleaved in ultrahigh vacuum. Current‐voltage (I‐V) measurements provide a detailed view of the variation in Fermi‐level position across the superlattice. The I‐V curves show the clear signature of nondepleted n‐ and p‐type material, with depleted regions appearing at the interfaces between n‐ and p‐type layers. The number of states available for tunneling is found to provide the major source of contrast in the images.