Optical response of TiO₂ layers, prepared by R.F. sputtering from TiO₂ target, was studied as a function of target state, oxygen partial pressure and sputtering power. We have found that TiO₂ layers deposited from a used target exhibit a high absorptance which decreases greatly when an oxygen partial pressure is introduced. Whereas an increase of sputtering power leads to an absorbent TiO₂ matrix.