The book describes the physical processes involved in generating intense beams of electrons and ions. It systematizes the main results of the technological interaction of accelerated electrons and ions with materials. It examines the deposition of thin layers by ion sputtering and electron beam evaporation. The processes of microelectronic structure processing by ion etching, ion implantation, electron and ion lithography are described. Data on modern methods for analyzing surfaces and microstructures with electron and ion beams are provided. The ongoing processes, the current state and achievements of electron beam welding, electron beam melting and refining, as well as electron beam and ion beam surface modification of materials are described and analyzed. Data on the design and operating principle of the devices are provided, methods for selecting technological modes are described, algorithms for computer modeling of the processes are presented, and the results of numerical experiments conducted by the author and his colleagues are discussed.