It is good news for people working in the field of plasma physics that this book, which has been out of print for many years is again available. Plasma Diagnostics, edited by W Lochte-Holtgreven, covers in 15 chapters important aspects of diagnostic methods and their theoretical backgrounds. The subjects, ranging from spectroscopy, via probe measurements to laser-aided techniques have been treated by specialists in the field. The emphasis is put on a clear and detailed presentation of the theoretical background in a form which is easily accessible to the experimentalist. Whenever necessary an introductory chapter establishes the fundamentals leaving the more practical aspects of the diagnostic method to separate contributions. The chapters on plasma radiation and spectroscopy and Langmuir probes refer essentially to low-temperature plasmas (in space or in the laboratory); however, x-ray diagnostics (chapter 7), the laser methods (chapter 9) and the microwave techniques (chapter 8) are equally well established with high temperature plasmas encountered in thermonuclear fusion devices. Of course, given the fact that the book is reprinted in its original form (American Vacuum Society Classics series), it does not take into account recent developments in the field. The description of the technical aspects represents the state of the art in the late 1960s. Nevertheless, it has to be regarded as a reference and has kept its value as a compilation of knowledge that otherwise would be dispersed in the original literature. In my opinion the senior scientist will appreciate that a well established textbook, which has been a reference for many years is again available. The introductory chapters will help the student or junior scientist to acquire the background which is necessary to understand more recent publications. Students will certainly appreciate the fact that an excellent textbook can be obtained at an affordable price.