This book has its origins in the intensive short courses on scanning elec­ tron microscopy and x-ray microanalysis which have been taught annually at Lehigh University since 1972. In order to provide a textbook containing the materials presented in the original course, the lecturers collaborated to write the book Practical Scanning Electron Microscopy (PSEM), which was published by Plenum Press in 1975. The course con­ tinued to evolve and expand in the ensuing years, until the volume of material to be covered necessitated the development of separate intro­ ductory and advanced courses. In 1981 the lecturers undertook the project of rewriting the original textbook, producing the volume Scan­ ning Electron Microscopy and X-Ray Microanalysis (SEMXM). This vol­ ume contained substantial expansions of the treatment of such basic material as electron optics, image formation, energy-dispersive x-ray spectrometry, and qualitative and quantitative analysis. At the same time, a number of chapters, which had been included in the PSEM vol­ ume, including those on magnetic contrast and electron channeling con­ trast, had to be dropped for reasons of space. Moreover, these topics had naturally evolved into the basis of the advanced course. In addition, the evolution of the SEM and microanalysis fields had resulted in the devel­ opment of new topics, such as digital image processing, which by their nature became topics in the advanced course.