Ionically crosslinked latex membrane is prepared by treating the latex membrane containing carboxyl groups with salt solutions. Pervaporation separation with these membranes shows that the ionic crosslinking raises the permeability, with the selectivity being maintained or increased. Ionically crosslinked membranes also have a higher pervaporation separation efficiency than the nontreated membranes. Permeability and selectivity increase with increasing ethanol content in feed. The temperature dependence of permeability can be correlated by the Arrhenius relationship.