The paper analyzes from experimental point of view the energetic and exergetic characteristics of a gas turbine plant (GTP) with heat recovery boiler (RB). For the experimental study of the cogeneration plant are represented the dependences of the thermodynamic parameters and the exergetic flows of the working fluids in the characteristic operating regimes. Unlike the experimental results obtained for the thermal power of RB, those who regard the second principle of thermodynamics conclude the scientific importance of the exergetic analysis.