Flow characteristics of gases in flow channels of 3-4 nm in diameter were studied experimentally. As the nanoscale channels, silica-surfactant nanocomposite membranes having rather uniform diameters and straight channels were used. The flow characteristics were investigated by changing gas temperature from 20 to 60 ℃ and kinds of gases, N_2, Ar, He, CO_2 and R-134a (hydrofluorocarbon). As the results, the possibility is presented that the flow in the nanoscale channels is a mixture of rarefied gas flow and surface diffusion flow.