Gas transport properties of PIM-EA(H2)-TB, a microporous Tröger’s base polymer, were systematically studied over a range of pressure and temperature. Permeability coefficients of pure CO2, N2, CH4 and H2 were determined for upstream pressures up to 20 bar and temperatures up to 200 °C. PIM-EA(H2)-TB exhibited high permeability coefficients in absence of plasticization phenomena. The permeability coefficient of N2, CH4 and H2 increased with increasing temperature while CO2 permeability decreased with increasing temperature as expected for a glassy polymer. The diffusion and solubility coefficients were also analysed individually and compared with other polymers of intrinsic microporosity. From these results, the activation energies of permeation, diffusion and sorption enthalpies were calculated using an Arrhenius equation.