The combustion of coal, which is based on the Polish energy sector is accompanied by co-firing of biomass. The use of this renewable energy source can also carry risks arising from potential contamination with heavy metals biomass. The aim of the study was to estimate the contents of Cd, Pb, Zn and Cu in various types of biomass used to produce electricity in a Polish power station. The biomass mineralized in a dry method. The contents of the analysed elements were determined by FAAS. Type analysed biomass had an impact on the compactness of the investigated metals. The contents of cadmium, lead, zinc in different types of biomass were characterized by great diversity, the coefficient of variation was 92% (Cd), 89% (Pb) and 80% (Cu). The zinc variability was average (V = 37%). Cadmium content in the pellet with straw and wood briquette and the content of zinc and copper in pomace oil, sunflower pellet, pellet, straw and wood briquette exceed typical values ​​for these types of biomass contained in the standard.