To provide an internal combustion engine for supplying heat, electricity and cryogenic heat by lowering the fuel fee of the internal combustion engine to one half and eliminating the discharge of pollutant including CO2, so as to prevent global warming and restrict the electricity rate.

An outer wall of a combustor-cum-heat exchanger of a steam/gas combined turbine engine is formed into the spiral water cooling outer wall unit assembly structure including a conducting tube, and is arranged as a honeycomb having multiple small-diameter holes by miniaturing and pressurizing. One or more spiral annular conducting tubes are provided in the assembly, and the fuel which is about four times that of the conventional technology is converted to the superheated steam as much as possible with the same quantity of the compressed air with the conventional one by injecting the maximum quantity of the superheated steam in the atmosphere of non-NOx, superheated steam suction thermal lean burn and high pressure, so as to generate the energy to be supplied to the steam turbine 10 times of the latest combined power plant, and the condensate fixed combustion gas is restricted to 0, and the thermal efficiency of the steam/gas combined turbine engine is raised to 80%, including the cryogenic heat supply at 0°C or lower of the exhaust temperature of the gas turbine.