The proposed book is the first attempt to outline a training course in radiation biophysics of non-ionizing electromagnetic radiation (EMR) of the radio frequency and microwave ranges. The tutorial consists of three logically related parts. The first part shows the main physical characteristics of EMP, classification of radiation, their natural and man-made sources. Biophysical laws of interaction of radio-frequency and microwave EMP with biological objects are considered. The second part describes the features of energy absorption and the mechanisms of biological action of EMP. Problems of theoretical and practical dosimetry are considered, mechanisms of thermal and non-thermal action of EMP are analyzed. The third part is devoted to the action of EMP on a person, issues of hygienic rationing and methods of protection against radiation. The main modern directions of EMR application in therapy and medical diagnostics are given.