High-resolution electron microscopy (HREM) has become a powerful method for investigating the internal structure of materials on an atomic scale of about 0.1 nm. This work explains both the theory and practice of HREM for materials science. In addition to a fundamental formulation of the imaging process of HREM, there is detailed explanation of image simulation for interpretation of high-resolution images. Information on appropriate imaging conditions for observing lattice images and structure images is presented, and methods for extracting structural information from these observations are shown, including examples in advanced materials. Dislocations, interfaces and surfaces are dealt with, and materials such as composite ceramics, high-Tc superconductors, and quasicrystals are also considered. Included are sections on instruments and techniques, such as the imaging plate and quantitative HREM.