In the field experiment the influence of fertilization with fresh waste activated sludge applied at varied rates as well as mineral fertilizers (NPK) on the content of selected elements (P, K, Ca, Mg, Na, S, Fe, Mn) in the biomass of Miscanthus sacchariflorus and in soil taken in the third and fourth experimental year was studied. The content of selected elements in the biomass of Miscanthus sacchariflorus plant and soil were determined with the ICP-AES (plasma-atomic emission spectrometry) method after mineralisation of samples by the ,,dry combustion” method in a muffle furnance. The content of determined elements in the biomass of Miscanthus harvested in the third year was higher than in the fourth year of cultivation, with the exception of phosphorus. The influence of the doses of waste activated sludge and mineral fertilizers on the content of selected elements was negligible. The application of fertilizers caused that the content of determined elements in the biomass of Miscanthus harvested in the fourth year of cultivation from those objects was lower that in biomass harvested from the control object. The content of determined elements (P, K, Ca, Mg, Na, S, Fe, Mn) in the soil taken from differential objects after the third and fourth year of cultivation of Miscanthus decreased in comparison to the content of those elements determined in the soil before starting the experiment.