Electron microscopes enable the observation of fine microstructures by using electrons, which have much shorter wavelengths than visible light. They are widely used across a broad range of fields, from inorganic materials such as metals, ceramics, and semiconductors to polymers and biological tissues.
Electron microscopes are broadly categorized into scanning electron microscopes (SEM), which observe surface structures using signals such as secondary and backscattered electrons generated by interactions between an electron beam and the sample surface, and transmission electron microscopes (TEM) and scanning transmission electron microscopes (STEM), which observe internal structures by detecting electrons transmitted through thin specimens.