The backstepping technique was used in order to synthesise a non-linear control law for the non-linear model of the power plant station. The non-linearities in the model are related to steam flow through the super-heater and the action of turbine valve. The time constant of the boiler is considered as a constant but unknown parameter. Its value has to be adapted. The backstepping procedure gives a straightforward way to implement the law of adaptation, which ensures the stability. Symbolic computations were used to derive control law. The simulations carried out have shown that the adaptive non-linear control system performs with the same quality in the whole range of operation and the adapted parameter tends to its nominal value.