The study of hydrogen recovery from a H₂-N₂ gas mixture was conducted both theoretically and exprimentally. For the application to the system which exhibits the intermediate trend between perfect-mix and no-mix （cross-flow） models a new model was formulated. Pure gas permeabilities of silicon rubber, polyethylene and microporous aluminum films were measured at 25 ℃. The silicon rubber of these was tested as a separation membrane using binary gas mixtures and the effect of stage cut and feed composition was examined experimentally. In comparison with mathematical models it was found that the present permeation characteristics are reasonably well represented by the no-mix model.