Issues of theory and practice of information protection by technical means. Considerable attention is paid to the physical nature of the occurrence of information signals in electromagnetic, electrical, acoustic and vibroacoustic channels of information leakage, methods of calculating parameters Means of identification of technical channels of information leakage and protection of information from leakage are considered in detail. A separate section is devoted to technical means of protecting objects. The classification of the main technical channels of information leakage taking place in real conditions is given. Issues of technical control of the effectiveness of information protection measures and certification of informatization objects are considered. Suggested options for practical tasks. The annex provides the technical characteristics of some devices for identifying and protecting information leakage channels. For students of higher educational institutions studying in the field of information security .