The book "UV-Visible Reflection Spectroscopy of Liquids" offers a comprehensive introduction to the theory and practice of reflection spectroscopy of liquids. It highlights the physicochemical properties of water and other liquids that are crucial for life sciences and industrial applications. The authors, Jukka A. Räty, Kai-Erik Peiponen, and Toshimitsu Asakura, discuss the challenges of monitoring process liquids and present optical measurement techniques that can be used for quality inspection of both transparent and turbid liquids. This specialized book is aimed at both beginners and professionals working in academic or engineering fields. It is particularly useful for physicists, chemists, and engineers involved in optical spectral analysis and the practical application of reflection metrology.