Abstract: A multichannel X-ray spectrometer comprises, in each spectrometric channel, individual holders for a focusing crystal analyzer and for an outlet slit, which are placed on a base and made as cylindrical supports equipped with slit locks. Cylindrical sockets are provided on the end face of the base and arranged adequately with respective cylindrical supports. Each socket has its own cylindrical support placed therein so that the slit locks envelop side surfaces of the base. The axes of the cylindrical supports coincide with the central generating line of the crystal analyzer and the outlet slit, respectively, and are spaced apart to a distance equal to 2R (1-2.delta.) sin .theta., where R is the radius of the focusing circle of the focusing crystal analyzer, .delta. is the mosaic structure factor, and 0 is the Bragg reflection angle. The end face of the base between the cylindrical sockets has an angle equal to 180.degree.-2.theta..