Results are given of the measurements of field effect and surface recombination velocity on HF-H2O2 treated germanium samples in air, nitrogen, and vacuum. It is found that the quiescent potential, state density, and surface recombination velocity depend on the amplitude of the field voltage at a given frequency. Although it is generally possible to explain the data for the region near the middle of the gap by assuming one discrete set of recombination centers and one discrete set of inactive states, both near the center of the forbidden gap, a continuous distribution cannot be ruled out. n-and p-type samples appear to have different state structures. In addition to the maximum at the center of the gap, which is common to all samples studied, the recombination velocity on n-type samples increases again at more negative surface potentials. For p-type samples indications of a second peak at positive potential are found. © 1963, The Electrochemical Society, Inc. All rights reserved.