Nonlinear Spectroscopy of Interfaces provides a timely and comprehensive treatment of surface-selective nonlinear spectroscopy, from fundamental theory and experimental techniques, to the latest applications. Author A. Morita reviews the range of applications of these techniques, from the historical sketch to the most recent advances that have greatly advanced microscopic understandings of soft and/or wet interfaces. The text addresses applications in water and aqueous solution surfaces, orientational analysis of organic molecules at interfaces, local structure of liquid-liquid interfaces, and various interfaces in the materials science and the biological sciences.