Abstract: Method and apparatus for the fast inspection of objects for the detection of elementary or compounded metals of the kind that are capable of producing with impinging X-radiation within the range of 60-160 KeV a detectable photoelectric interaction. A 110-160 KeV X-ray source is used in association with collimating and filtering apparatus, capable of generating a collimated X-ray beam consisting of repeating cycles comprising each one energy bin having a flux centred around the K-edge energy of the target metal and, if desired, comprising additionl energy bins. There is also provided a linear array of solid state, spectroscopy grade detectors.