Abstract The electron stimulated desorption of negatively charged hydrogen ions from diamond surfaces is studied with respect to an application as a bright ion source. Desorption of macroscopic currents of negative ions from a diamond surface by stimulated desorption has been demonstrated recently. To determine the dependence of the ionization cross-section on electron affinity, an oxygen covered diamond was used as a model system for positive electron affinity diamond. On this surface, different amounts of deuterium have been adsorbed. The D − ionization cross-section has been proven to vary by one order of magnitude between 3.5×10 −18 cm 2 and 5×10 −19 cm 2 with hydrogen coverage of the surface. The energy distribution of desorbed negative ions has been measured by an electrostatic analyser. For the measured broad energy distribution, an attempt of an explanation is made.