This is a first attempt to provide a general analysis of developments in polyimide membrane synthesis and applications. It will serve as a valuable reference for those with an interest in synthesis of polyimides, the chemistry and physical chemistry of polyimide compounds, the separation properties of membranes and in their preparation and application. It is intended as a summary of the current status of polyimide membrane research for the specialist as well as a teaching aid for graduate studies in polymer chemistry. The authors collaboration demonstrates the high level of scientific research in Russia and the active development of applied research in Japan.