The electron microscope (EM) is used as an important analytical method in the physical, chemical and biological sciences. Compared with light microscope, scanning electron microscopy (SEM) and transmission electron microscope (TEM) use electrons to image tissues at much greater magnification, so EM becomes an essential diagnostic tool to screen human tissues at high magnification and allows for visualization of details within cells. As a powerful tool for visualizing the tissues, cells, virus, nanomaterials as well as other biopsy, TEM is particularly important in tumor pathology, neuropathology, kidney disease, and so on