Aerosol-gel process has been used for the deposition of SiO2 thin films. Layers were deposited from a solution with pH = 3.5 and water to TEOS molar ratio (rw) 2.2 and then treated at various temperatures ranging from room temperature to 700 degrees C. As-prepared thin films have been characterized by FTIR spectroscopy. Spectra were acquired in transmission at 65 degrees angle of incidence or at perpendicular incidence. Characteristic absorption bands of the SiO2 sol-gel system have been studied with respect to the posttreatment temperature. Bands located at 1250-1000 cm(-1) and around 960 cm(-1) have been deconvoluted in several peaks. The origin and temperature dependence of these peaks are discussed.