Abstract: A multichannel X-ray spectrometer includes an X-ray tube with a transmission target and a holder for a specimen placed opposite the target, and spectrometric channels arranged around the specimen. These spectrometric channels include, successively arranged downstream fluorescent X-rays of the specimen, a common inlet annular slit with a radius R, focusing analyzer crystals, outlet slits, and detectors of X-rays. The common annular slit is spaced from the reference surface of the holder to a distance h equal to 0.5 R, where R is 0.5 dD/2L, where d is the diameter of the outlet port of the transmission target, D is the diameter of the fo-fusing ring of the focusing analyzer crystals, and L is the length of one of the focusing analyzer crystals.