Diamond has a number of unique chemical and physical properties. In particular, when covered with hydrogen, diamond surfaces acquire a negative electron affinity (NEA). This NEA property has already been used to fabricate high-efficiency diamond-based light detectors and/or electron emitters.We have used the scanning tunnelling microscope for (i) atomic-scale visualisation of the hydrogenated diamond surface, (ii) probing the surface electronic structure and (iii) atomic-scale desorption of hydrogen atoms. Desorption of individual hydrogen atoms has been used to pattern pre-selected areas on the hydrogenated diamond surface. This is considered to be a promising way to fabricate atomic-scale photon detectors and/or electron emitters. The feasibility of the tip-induced atomic-scale desorption of hydrogen from the diamond surface is discussed in comparison with the similar studies on hydrogenated silicon and germanium surfaces performed previously.