This book emphasizes both experimental and theoretical aspects of surface, interface and thin film physics. Compared to the earlier editions, which bore the title "Surfaces and Interfaces of Solid Materials", the book now places more emphasis on thin films, including also their superconducting and ferromagnetic properties. The present 4th edition thus presents techniques of preparing well-defined solid surfaces and interfaces, fundamental aspects of adsorption and layer growth, as well as basic models for the description of structural, vibronic and electronic properties of surfaces, interfaces and thin films. Because of their importance for modern information technology, significant attention is paid to the electronic properties of semiconductor inter- faces and heterostructures. Collective phenomena, such as superconductivity and ferromagnetism, also feature prominently. Experimental sections covering essential measurement and preparation techniques are presented in separate panels.