The monograph covers the results of research activities of the laser laboratory of the automobile plant named after I.A. Likhachev - the base laboratory of the Research and Development Center of the Academy of Sciences of the USSR for the period 1975-1985. The thermophysical foundations of laser hardening, scientific and technical aspects of laser hardening, welding, and cutting processes are considered. Data on changes in structures and properties in laser exposure zones for various materials are given. Particular attention is paid to the issues of diagnostics and control of laser processing processes. Features of practical implementation of laser processes in industry are discussed.