Three components of the background have been investigated: first, characteristic radiation of the lamellas of the collimator excited by secondary x-ray beam; second, secondary x-ray beam scattered by the lamellas of the collimator; third, diffusive and incoherent scattering of the secondary x-ray beam by the focusing crystal. The relationships between chemical content of the specimen and the intensity of the first and the second components were determined by a wavelength-dispersive x-ray spectrometer that has an energydispersive x-ray detector. The intensity of the third component was very low. It was not found in this experiment. 304 P. O. Verkhovodov allows absorption correction to be done in the determination of elements in the medium of heavy elements. A procedure for noble metal testing in powder samples was created.