Gas transport characteristics (permeability and diffusion and solubility coefficients for CO2, O-2, N-2, H-2) of new crosslinked membrane materials synthesized by copolymerization of poly(ethylene glycol) dimethacrylate and poly(ethylene glycol) methyl ether methacrylate in the presence of various ionic liquids have been studied. Comparison of the characteristics of specimens with and without ionic liquids has revealed that the presence of ionic liquids enhances the permeability of the membranes, especially to CO2. It has been shown that the enhancement of the CO2 permeability of films incorporating ionic liquid is due to an increase in CO2 solubility and the increase in selectivity for pairs of gases containing CO2 is determined by thermodynamic selectivity of separation.