This scientific study presents new results of research, performed by the Tula scientific school of field and radiation biophysics (under the direction of A.A. Yashin), relating to the impact factor of the external low-intensive electromagnetic radiation EHF (30-300 GHz) upon the reproductive function and postembryonic development of mammals, including the characteristics of spermatogenesis and late effects in the offspring. Mathematical models have been developed, reflecting the reliability of the received results of experiments on laboratory animals. They allow predicting long-term consequences of electromagnetic field exposure upon the reproductive function. The obtained results can be used in clinical medicine to assess the impact of pathogenic fields in groups of professional risk. The book written is edited by O.V. Tereshkina - Candidate of Biological Sciences, Docent. It is intended for researchers, graduate students and students of biological and medical specialties.