The reference book contains the main physicochemical constants, data on phase equilibrium and behavior of various substances at low temperatures, as well as production parameters necessary for the design of deep cooling plants. The most important schemes of industrial plants for separation of air, natural gas, coke gas, pyrolysis and cracking gases are described. Description of the main refrigeration cycles and their thermodynamic characteristics are also given. The reference book is intended for engineers and technicians working in the field of separation of gas mixtures by the method of deep cooling.