Transmission electron microscopy (
TEM) is a
microscopy technique in which a beam of
electrons is transmitted through an ultra-thin specimen, interacting with the specimen as it passes through it. An image is formed from the interaction of the electrons transmitted through the specimen; the image is magnified and
focused onto an imaging device, such as a
fluorescent screen, on a layer of
photographic film, or to be detected by a sensor such as a
CCD camera.