This new volume in the series Physics and Chemistry of Materials with Layered Structures satisfies the need for a comprehensive review of the progress made in the decade 1972-1982 in the field of the electronic properties of layer compounds. Some recent theoretical and experimental developments are highlighted by authori tative physicists active in current research. The previous books of this series covering similar topics are volumes 3 and 4. The present review is mainly intended to fulfill the gap up to 1982 and part of 1983. I am indebted to all the authors for their friendly co-operation and continuous effort in preparing the contributions in their own fields of competence. I am sure that both the expertise scientists and the beginners in the field of the electronic properties of layered materials will find this book a valuable tool for their research work. Warm thanks are due to Prof. E. Mooser, General Editor of the series, for his constant and authoritative advice. * * * This book has been conceived as a tribute to Prof. Franco Bassani to whom the Italian tradition in the field of layer compounds, as well as in other fields of solid state physics, owes much. The authors of this review have all benefited at some time of their professional life from close cooperation with him. Istituto di Struttura della Materia, VINCENZO GRASSO Universitd di Messina IX V Grasso (ed.). Electronic Structure and Electronic Transitions in Layered Materials. ix.