This book covers the most important issues of plasma - wall interactions in nuclear fusion devices. Several authors, all actively working in that particular field, have written articles on surface phenomena (erosion mechanisms, particle recyling, wall coatings and ablation) and bulk material properties (thermal stability, radiation damage). The latest developments and findings are provided. Nevertheless, the basic principles are also given for each issue in a concise style, such that this book may serve as an excellent introduction for everyone entering the field of plasma - wall interactions. For other scientists in fusion, in particular the non-specialists, this book provides a useful survey of the present status of plasma - wall interaction issues and the most important processes involved, a broad knowledge of which is of growing importance in solving the problems of energy and particle exhaust in fusion devices.