The manual covers both theoretical and practical issues related to the training of an instrument engineer. The chapters of the manual cover: the main groups of electrical materials, i.e. conductors, dielectrics, semiconductors and magnetic materials; classification of automation circuits, schematic-graphic and letter designations of circuit elements; ensuring uninterrupted power supply in the power saving mode, as well as the operation of power supply systems; instrumentation, installation, commissioning, repair work at modern industrial enterprises;