The polycrystalline silicalite membrane was prepared on a porous sintered stainless steel support and its pervaporation performance was investigated using a MeOH/MTBE mixture as a feed. It was found that the MeOH selectivity of pervaporation is considerably higher than that of distillation. This indicates that the silicalite membrane permeates methanol preferentially. From the results of the competitive adsorption experiments and the temperature dependence of permeation rates of MeOH and MTBE, it was suggested that the selective sorption of MeOH into the membrane takes place and that the transportation of MTBE within the membrane is strongly suppressed as compared with that of MeOH.