Abstract: An apparatus for performing extend X-ray absorption fine structure (EXAFS) measurements on materials. The EXAFS apparatus is constructed using a conventional X-ray powder diffractometer assembly with a rotating anode X-ray source affixed to the diffractometer assembly, a monochromator crystal rotatably positioned at the center of the assembly and a specimen stage and detectors slidingly mounted on a receiving track of the assembly. The monochromator crystal is automatically and elastically distorted to provide a monochromatic X-ray beam flux from the crystal. The angle of incidence of the source X-ray beam with the crystal surface is changed to provide a different monochromatic X-ray wavelength with changing energy, which enables measurement of the desired EXAFS spectra for the material.