This reference focuses on the branch of electron spectroscopy generally labelled as either Electron Spectroscopy for Chemical Analysis (ESCA) or X-ray Photoelectron Spectroscopy (XPS). It emphasizes the use of core level and valence band binding energies, their shifts and line widths. It describes the background, present status and possible future uses of a number of recently developed branches of ESCA, including the changing shift and Fermi edge referencing, valance band analysis, XPS-induced loss spectroscopy, surface-to-bulk chemical shifts, small cluster analysis, photoelectron...