This brochure, written on the materials of domestic and foreign press, in a popular form sets out the basics of infrared technology and tells about its use in military affairs. Infrared technology is associated with the use of radiant energy in the infrared region of the spectrum. In 1870. English astronomer Herschel studied the solar spectrum obtained by him with the help of a prism. By placing a mercury thermometer in various parts of the spectrum and beyond, he noticed that the thermometer is significantly heated beyond the spectrum of the solar beam, although no visible rays fall on it. These invisible rays, which heated the thermometer, were called infrared because they are located behind the red part of the solar spectrum. Thus, infrared rays were discovered, which have a wavelength of about 0.8 microns .. In the future, scientists have discovered a whole area of infrared rays, having a wavelength of 0.8 microns to several hundred. During the Second World War, infrared equipment was used in the troops for observation, communication, fire control. The program of the CPSU, adopted by the XXII Congress of the Party, among the main tasks in the field of science, set the problem of intensive development of radio electronics, the beginning of which was laid by our great compatriot the scientist and inventor A. C. Popov. Infrared technology as one of the most important areas of radio electronics has to play a very responsible role. Already, infrared technology is widely used to solve various problems in industry, agriculture, medicine, astronomy, military affairs, etc. d. Infrared technology will be even more widely used in connection with the achievements of a new field of science - quantum radio electronics - and the creation of quantum devices that work on infrared rays. Further development of the technology will require new solutions to important and complex tasks in the field of infrared engineering. This brochure introduces the reader to the basics of theory and the technical means of solving these problems.