Tungsten tip electron source, microchannel plate, phosphor screen, high voltage source, and Ultra High Vacuum Chamber are used to build up the Field Ion Microscope in this paper. By setting up the system and detailed describing the operating process, guide students to complete experimental procedures such as tip preparation and modification, field ion imaging, and liquid nitrogen cooling. The experiment shows that by liquid nitrogen cooling the resolution of FIM can be improved sufficiently which provides higher clarity images for atomic-level imaging and manufacturing.