The need for a new edition of Hans Reiter's monograph 'Classical harmonic analysis and locally compact groups' has been felt for a long time. His original book has had a considerable impact on several parts of harmonic analysis. Its style and organization distinguish it from other books on similar topics. Remarkably, after more than thirty years, the book has lost very little of its mathematical relevance. Radical Banach algebras and amenable groups—to mention only these—are flourishing subjects of research nowadays. For both subjects, and for several others, the book contains valuable information.