1 Introduction -- 2 Metallic point contacts as a physical tool -- 3 Fundamentals of PCS theory -- 4 Experimental techniques -- 5 PCS of quasiparticle excitations -- 6 PCS of nonphononic scattering mechanisms -- 7 Thermal effects in point contacts -- 8 Point contacts in the magnetic field -- 9 Electrical fluctuations in point contacts -- 10 Point contacts under irradiation -- 11 PCS of semimetals, semiconductors, and dielectrics -- 12 PCS of superconductors -- 13 PCS of high-Tc and other uncommon superconductors -- 14 PCS of heavy-fermion systems -- 15 New trends in research.A new type of spectroscopy, Point-Contact Spectroscopy, was created for the study of conduction electron interaction mechanism with a class of elementary excitations in solids. The goal of this book is to introduce readers to Point Contact Spectroscopy. The physical principles of spectroscopy of quasi-particle excitations in metals at low temperatures by means of point contacts are presented. The point contact constitutes a tiny metallic bridge connecting bulk electrodes. Along with the most thoroughly studied phonon excitations, the interaction of electrons with other quasiparticles (magnons, crystal-field electron excitations, paramagnetic impurities, two-level systems, etc), are reviewed. Various experimental techniques for point contact production are described. Examples of point-contact spectra are presented for pure metals, alloys and compounds, as well as for semimetals and semiconductors, high-Tc and other exotic superconductors, heavy fermion systems, Kondo-lattices, mixed valence compounds and more. Special attention is paid to contact conductance behavior in superconducting states, in high magnetic fields and under high-frequency radiation. The theoretical part of the book is restricted to presenting the main relations without superfluous details. Point-Contact Spectroscopy includes more than 200 figures.