Synthetic Membranes as a Field for Chemical Reaction Review from the View Point of Membrane Design Shigeyoshi HARA * and Takeyuki KAWAGUCHI * Synthetic membranes which have function as a field separation and reaction are reviewed on the basis of membrane design. Among these are included membranes for reverse osmosis, dialysis, ion exchange, gas separation,pervaporation, perstraction, facilitated transport, active transport, chiroselective transport, electron transport, and enzymic reactions.