Directions of development of technology of diffusion welding of metal and non-metal materials are considered. Theoretical bases of interaction of dissimilar materials with intermediate layers of ultrafine powders of metals and their mixtures are described. A description of the process of obtaining highly active energy-saturated layers by the method of thermal decomposition of organometallic salts is given. Technologies of diffusion welding of specific materials are considered. Information on modern welding equipment and specialized technological equipment is presented.