Simulation and experimental studies on the double pipe (shell and tube) polymer membrane reactors were examined for the vapor-phase methyl tert-butyl ether (MTBE) decomposition. H3PW12O40 catalyst supported on silica was used as an active catalyst for the reaction, Polyphenylene oxide (PPO), polysulfone (PSF) or cellulose acetate (CA) membrane coated on the double-layered alumina tube was used as a constituent membrane. It was observed that permeabilities of methanol through each polymer membrane were higher than those of isobutene and MTBE regardless of the kind of polymer material used. The selective removal of methanol through polymer membrane shifted the chemical equilibrium toward a favorable direction in the model reaction. The MTBE conversions in the membrane reactors were much enhanced compared to the equilibrium conversions. The PPO membrane reactor showed the best performance under the experimental conditions. The simulation results on the performance of the membrane reactors were in good agreement with the experimental results within the error of +/-5%. It was revealed from the simulation that the CA membrane reactor showed the best performance at high contact time whereas the PPO membrane reactor showed the best performance at low contact time in terms of MTBE conversion, isobutene yield and isobutene selectivity. It was also observed that the performance of membrane reactor was much improved with the decrease of coating amount of polymer membrane and reaction temperature, but with the increase of partial pressure of MTBE, It was concluded that the simulation program developed in this work described the performance of the membrane reactor very well for the vapor-phase MTBE decomposition,