The third edition had been enlarged by the inclusion of new developments such as the direct observation of individual atoms in Paul traps and of atoms in molecules on solid surfaces using the scanning tunneling microscope. Furthermore, new experiments in atomic interferometry and the possibility of laser cooling of atomic beams were added. The fourth English edition takes minor corrections and additions into account and remains a unique introduction to both experiments and theory. The student will find 160 problems and their solutions, which make this book a real study text.