Abstract: Ion sources or generators for focused ion beam emission (FIB) applications emitting ion beams into vacuum or a gas are used in industry and research for the characterization and processing of surfaces. With appropriate focusing, such ion beams can be confined to diameters of a few nanometers. The tip of technical FIB generators for producing such focused beams consists of a liquid metal, gallium in general, which tends to fluctuate during operation. This has a negative influence on the stability of the emission current and the focus definition. It is also possible to generate an FIB with solid tips, consisting of a solid metal, but such tips deteriorate rapidly during operation due to erosion of material from the tip apex. The present invention concerns a novel FIB source generating free space ion beams from a solid source but does not exhibit the above-mentioned erosion effect at the apex.