The book describes the main physical processes that occur in electromagnetic screens and determine their shielding effect. The dependence of shielding efficiency on screen dimensions, on material and wall thickness and on frequency is considered. Much attention is paid to the effect on the effectiveness of shielding with holes and slots in screens. Calculation formulas and practical recommendations for screen design are given. The book is designed for a wide range of engineering and technical workers in the field of radio electronics and telecommunications, as well as teachers and students of relevant higher educational institutions.