The evolution of our understanding of most properties of new functional materials is related to our knowledge of their atomic-scale structure. To further this, several X-ray and neutron techniques are employed. The anomalous X-ray scattering (AXS) method, exploiting the so-called anomalous dispersion effect near the absorption edge of the constituent element, is one of the most powerful methods for determining the accurate partial structure functions of individual pairs of constituents or the environmental functions around specific elements in multicomponent systems. AXS is useful for both crystalline and non-crystalline systems, for studies of surface and bulk materials. This book is the first on this new method of structural characterization. It describes the basics and application principles, and also treats the specifics of application to liquid alloys, supercooled liquids, solutions, metallic glasses, oxide glasses, superconducting ionic glasses etc.