The development of the element base on which the systems and complexes given in Book 1-3 of this series. The element base of radioelectronic equipment is presented in accordance with the scale of electromagnetic waves (the considered range extends from decameter to optical). The various classes of active and passive devices and the physical principles on the basis of which they are created, as well as the materials and technologies with which they are made, are given. Systems and complexes of radar and electronic warfare are shown, in which certain components of the element base are used. The Appendices contain the main characteristics of the most important components of the element base, materials, technologies.