This book on Extended X-Ray Absorption Fine Structure (EXAFS) Spectroscopy grew out of a symposium, with the same title, organized by us at the 1979 Meeting of the Materials Research Society (MRS) in Boston, MA. That meeting provided not only an overview of the theory, instrumentation and practice of EXAFS Spectroscopy as currently employed with photon beams, but also a forum for a valuable dialogue between those using the conventional approach and those breaking fresh ground by using electron energy loss spectroscopy (EELS) for EXAFS studies. This book contains contributions from both of these groups and provides the interested reader with a detailed treatment of all aspects of EXAFS spectroscopy, from the theory, through consideration of the instrumentation for both photon and electron beam purposes, to detailed descriptions of the applications and physical limitations of these techniques. While some of the material was originally presented at the MRS meeting all of the chapters have been specially written for this book and contain much that is new and significant.