Pronounced changes in sodium surface concentration and chemical state were observed after electron bombardment of cleaved single crystal Naβ-alumina, which is known to exhibit unusually fast Na+ transport. In particular, a distinct increase in the sodium Auger signal started at a certain energy and current density of the primary electron beam and was always accompanied by a large surface charging. Thus, migration of Na+ under the influence of the induced electric fields was found to be the major process leading to the sodium segregation at the Naβ-alumina cleavage surface. Possible mechanisms for the segregation process are discussed. XPS measurements of the bombarded surface revealed the appearance of neutral sodium atoms as well as sodium-oxygen multilayer surface compounds. A simple method to obtain the electric potential distribution at the surface ("charging-map") is demonstrated. The sodium distribution on the Naβ-alumina surface after e-bombardment was found to be reflected in the corresponding charging-map.