Since the appearance of the first commercial scanning electron microscope (SEM) three decades ago, major advances were achieved in resolution, new electron probe sources, the development of additional modes, and computerization (including built-in image store capabilities in the current generation of instruments). These advances were accompanied by an increasing number of applications in a wide variety of fields, and the SEM became an indispensable tool in various fields of research providing a wealth of information on physical, structural, and compositional properties of a wide range of materials.