The textbook outlines the foundations of the theory of electrical devices as a single electromechanical complex, including current-carrying elements, contacts, insulating structures, arc suppressors, drive devices and electromagnetic mechanisms; description of physical processes accompanying operation of electric devices during operation is given. The textbook is written on the basis of many years of experience in teaching the course "Electrical devices" and performing research in all its sections by the team of the department of electrical and electronic devices.