The 3rd edition was extended by the chapter "Novel Future Ferrites - Hexagonal Ferrites". The reader is thus given the basics of the various shielding effects in a compressed form. This book is addressed to engineers, scientists, students, researchers and specialists from the practice. Shielding for ensuring EMC in high-frequency and radar technology has been developing with ever increasing dynamics since about 1960. The understanding of the interaction of a magnetic material and the resulting phenomenon of shielding is illustrated by simple examples and practical applications.