This paper describes the solution of heat and mass transfer problem in the little-size combustion chamber. The mass, momentum and energy conservation equations were solved numerically. Turbulence was modelled using standard $k-\varepsilon$ chemical reaction velocity and one-step reaction. The problem was solved using two energy conservation equations – for enthalpy and for temperature, which was necessary for a fine treatment of conjugate heat transfer problem on the cooled wall of combustion chamber. The fuel, oxidizer and temperature distributions show that specially organised flow in combustion chamber satisfies requirements of high mixing level and flame stabilisation.