The subject of the thesis is condensing steam turbine with the required power of 50MWe and set input and output parameters. The turbine is designed as a two-body turbine. There is also designed balance scheme with reheating, regeneration and air condenser. Subsequently, the thermodynamic calculation for three variations of high pressure part with different speeds is demonstrated. The result is evaluated in terms of calculated efficiency and also in an economic point of view. The output is a selection of the variation with the best parameters. Then the basic dimensioning calculations, the design of the leveling piston and the sealing system follows for this variation. A simplified section of this part is drawn. Finally, the balance scheme is...