Our German textbook "Festkorperphysik" has meanwhile appeared in its th nd 6 edition, extensively revised and extended in comparison to the latest 2 English edition. Presently, the book has been translated into Japanese, Kor ean and Polish and is used as a standard text in many universities around the world. It is therefore high time to carefully revise the English text and th bring it up to par with the latest 6 German edition. The sections on "High Temperature Superconductors" as well as Panel XVI on "Shubnikov-de Haas Oscillations and Quantum Hall Effect" are completely revised accord rd ing to the present deeper understanding of the phenomena. This 3 English edition has furthermore been expanded by several chapters to meet the edu cational requirements for recent fields of research. We let ourselves be guided by the idea that modern teaching of solid state physics emphasizes aspects of material science and its applications, in particular in solid state electronics. Accordingly, deviations from the ideal periodic solid have gained more weight in the text: we now consider phase diagrams of alloys, some basics of defect physics and amorphous solids. Because of the impor tance of strained layer systems in device physics, inclusion of the funda mentals of crystal elasticity theory seems (again) necessary, so a new chap ter is devoted to this topic.