A single-atom electron source was applied to a low-voltage scanning electron microscope. We developed a mounting technique of an electron emitter by using X-ray diffraction method, and a mounting stage which enables us the mechanical adjustment of the emitter's tilt angle as well as its XY positions. It was made possible to align the emission direction precise enough for the electron optics of the microscope. In the trial operation, a spatial resolution of 1.7 nm was achieved at an acceleration voltage of 5 kV by using a ZrO/W Schottky electron emitter. At present, the mounting of a single-atom electron source is in progress.
