The surface states of germanium have been investigated by measuring the change in conductance occurring upon cleavage along a (111) plane, in liquid nitrogen. Experiments were carried out with n-type samples whose donor concentrations varied from 10 13 to 10 18/cm 3. The measurements were made on p-n-p structures which upon cleavage form a p-type channel across the n-type base. It is found that at the low temperature of the experiment and with the large electric field existing at the surface, quantum mechanical effects arise in the space charge region. The analysis was carried out for a pseudo two-dimensional space charge region, and for two extreme values of the hole mobility. The results are related to two models of the surface energy spectrum for the excess electrons: 1) a discrete level with 1.44 × 10 15 states/cm 2, 2) a 20 eV wide band of levels with 7.22 × 10 13 states/cm 2·eV. It is shown that the heavy holes in the space charge region are more likely to move with a mobility close to their bulk mobility. The neutral point of acceptor-like surface states is found to lie 0.06 ± 0.03 eV above the first allowed level for heavy holes. From the data it is not possible to obtain a unique determination of the distribution of states in the forbidden gap.