This 1996 book summarises the state of knowledge on the microscopic behaviour of oxide surfaces.This book summarizes the present state of knowledge on the microscopic behaviour of oxide surfaces. Chapter 1 summarizes classical approaches, introduces the concept of ionicity, and describes the mixed iono-covalent character of the oxygen cation bond in bulk materials. The next three chapters focus on the characterisitics of the atomic structure, the electronic structure and excitations of clean surfaces. Metal oxide interfaces are considered in chapter 4. The last chapter discusses the concepts underlying acid-base reactions on oxide surfaces, and their applicability to the adsorption of hydroxyl groups.This book summarizes the present state of knowledge on the microscopic behaviour of oxide surfaces. Chapter 1 summarizes classical approaches, introduces the concept of ionicity, and describes the mixed iono-covalent character of the oxygen cation bond in bulk materials. The next three chapters focus on the characterisitics of the atomic structure, the electronic structure and excitations of clean surfaces. Metal oxide interfaces are considered in chapter 4. The last chapter discusses the concepts underlying acid-base reactions on oxide surfaces, and their applicability to the adsorption of hydroxyl groups.This book summarizes the present state of knowledge on the microscopic behavior of oxide surfaces. It includes classical approaches, introduces the concept of ionicity, and describes the mixed iono-covalent character of the oxygen cation bond in bulk materials. It emphasizes the characterisitics of the atomic structure (relaxation, rumpling and reconstruction effects), the electronic structure (band width, gap width, etc) and the excitations of clean surfaces. Intended for graduate students in material science, condensed matter physics and physical chemistry, this book proposes theoretical models to clearly illustrate the experimental results obtained on givenl3%