The textbook, which is a lecture course for students of energy specialties, summarizes the basics of the theory of gas turbine, steam turbine and combined-cycle gas installations (CCGT) of thermal power plants. The description of the design features is given, the basic thermal schemes with steam turbines produced by JSC Ural Turbine Plant and Leningrad Metal Plant as part of a CCGT with heat recovery boilers are considered. The manual is intended for students of energy and power engineering specialties of universities studying the discipline "Combined cycle gas installations". It can be used by the operating personnel of thermal power plants, as well as in retraining and advanced training systems. This textbook was released with the support of the strategic academic leadership program "Priority 2030" (agreement 075-15-2021-1333 of 30.09.2021).