[en] A method to restore stoichiometry of zirconium and hafnium dioxides during their regeneration from wastes formed in case of plasma sputtering of the dioxides by the method of electron-beam evaporation has been suggested. The regeneration is realized by thermal treatment in oxygen-containing atmosphere. To increase the purity of final product initial oxides are subjected to boiling in 10-15 % hydrochloric acid for 30-40 min prior to thermal treatment. Complete washing off of acid is conducted at 50-60 deg C by bidistillate. Thermal treatment is carried out at 950-1050 deg C for 40-50 h. The content of impurities reduces from 0.02-0.03 to ≤ 0.005 mass %