Membranes and membrane processes are widely used in modern technologies. This field of knowledge is successfully developing in Russia and domestic scientists firmly occupy one of the leading positions in this direction. This monograph contains information about many types of membrane materials (ion exchange materials (including high-molecular ,). Inorganic , Bipolar (CM) Track , liquid membranes), methods of description and modeling of transfer processes in membranes , Methods of membrane research and the main directions of their use (membrane catalysis , water treatment , Hydrogen Energy , CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC nanofiltration and separation of liquids). Sections of this book are written by leading Russian scientists . The presented material can be considered as a reference publication and will certainly be useful to specialists, including scientific employees and technologists working in the field of development of various types of membranes or using membrane technologies in their work. On the other hand, in preparing the monograph, the authors tried to present the material in an accessible form. Therefore, it can be simultaneously considered as a teaching aid intended for teachers and students specializing in chemistry or chemical technology. To create a more complete picture of specific achievements and a deeper understanding of the problems in each section, references are made to the original works of both Russian and foreign researchers. The material is presented in a form accessible to a wide range of readers engaged in scientific work in this field, using it for practical purposes, and just wanting to get acquainted with some of the most significant results.