The manual is written on the basis of a course of lectures by prof. In. G. Low-cost «Electromagnetic interactions of nuclei» at the Faculty of Physics of Moscow State University. The main topic is the study of photonuclear reactions at average energies (from the threshold of peony birth to several GeV), when the wavelength of the incoming photon is comparable to the size of the nucleon. Such reactions are a simple and effective way of studying the structure of the nucleus at the level of nucleon and meson degrees of freedom. Data on the Coulomb dissociation of relativistic ions are discussed, which indicate new phenomena associated with the influence of strong electromagnetic fields on the nuclear substance. Astrophysical and Applied Applications . Modern methods of obtaining monochromatic polarized gamma beams of medium energy, as well as methods of computer data processing using modeling are described