The book "Practical Spectroscopy of High-Frequency Discharges" offers a comprehensive and practice-oriented introduction to the spectroscopic techniques for studying physical processes in high-frequency, electrode-less discharge lamps. It is the first work to detail both fundamental and applied methods while focusing on the design and optimization of these lamps. These lamps are not only a popular source for line spectra but also an important tool in ultra-precise optical technology. The authors, Sergi Kazantsev, Vyacheslav I. Khutorshchikov, Günter H. Guthöhrlein, and Laurentius Windholz, provide valuable insights into the practical applications and challenges of spectroscopy in this specific field.