In this paper a brief overview is presented of some of the techniques available with transmission electron microscopy (TEM) to characterize thin films and interfaces. The critical role that sample preparation plays is discussed. Examples of the application of many of the analytical techniques used in TEM are given. These include nano area electron diffraction, energy-dispersive X-ray spectroscopy and electron energy loss spectroscopy. High resolution imaging is available at atomic resolution and new methods are being developed to analyze the images including computer simulation. Imaging of magnetic domains is important to the study of materials used in digital data storage. © 1992.