The mechanism of interaction of industrial glassware with acid gases can be reduced to the dealkalization of the surface layer to a depth of approximately 1.0 µm, the degree of dealkalization reaches 80 %. Two– and three–component silicate glasses are dealkalized by acid gases at a depth of 30 µm. Thermochemical treatment of industrial glassware with acid gases increases their chemical resistance by several times, and the mechanical strength increases by 20-30 %, the thermal stability and microhardness  by 10–20 % [1]. Chemical resistance of glass containers is significantly increased when processed with fluorine– and chlorine–containing compounds [1–3]. The mechanism of this interaction has been insufficiently studied.  The aim of the undertaken experiments was to determine the possibility to use infrared reflectance spectroscopy to investigate the structure of the surface layers of container glass, treated with gaseous fluorine– and chlorine–containing reagents.   Objects of investigation were flat bottles and flasks of colorless glass. Difluorodichloromethane and difluorochloromethane were used as gaseous reagents. Thermochemical treatment of glass samples was held in laboratory and industrial conditions. The main regimes of glass treatment are the following: temperature – between 20 and 700 ⁰C, duration – between 1s and 120 minutes, volume of reagent for one treatment - between 0.1 ml and 30 l. IR spectra of reflection were recorded in the range of 400–4000 cm^-1.  On the IR spectra of the samples, obtained after thermochemical treatment with gaseous fluorine– and chlorine–containing reagents the strips in the range of about 960 and 1060 cm^-1 occupy a position with a higher wave number. The displacement of the peak in the range of approximately of 1060 cm^-1 indicates the enrichment of glass surface layer with silica. Accordingly, the increase of the wave number for the band in the range of 960 cm^-1 caused a decrease of Na⁺ concentration in the glass surface layers. This suggests that the thermochemical treatment of container glass with gaseous fluorine– and chlorine–containing reagents is accompanied by its dealkalization.  Change of the peak in the range of 470–480 cm^-1 can be used only for qualitative detection of glass dealkalization process by gaseous reagents, as the rate of change of this band is not sufficient for quantitative measurement and comparison. It has been established that the increase of the duration of treatment and volume of reagent for one treatment leads to the intensification of dealkalization process of glass.  The results obtained indicate the expediency of the application of IR reflection spectroscopy to investigate the structure of glass surface layers subjected to treatment with gaseous fluorine– and chlorine–containing reagents.