The of photochemical decomposition of XeO4 under the action of UV-radi
ation in the wavelength range of 200-300 nm was investigated. Tile qua
ntum yield of tile formation of oxygen atoms upon XeO4 photodissociati
on was measured (phi = 3.6+/-0.4). The results obtained point to tile
predominant role of the XeO4 + hv --> 4O + Xe photodissociation channe
l of XeO4. The value of the rate constant of the reaction XeO4 + O -->
O-2 + XeO3 was estimated (< 4.5 . 10(-16) cm(2) s(-1)).