Biogas is produced in the anaerobic digestion of biomass. It is a mixture of methane (mainly), carbon monoxide, hydrogen sulfide and water in vapor form. The concentrations of these gases vary depending on the type of fermentation process substrates, which affect the chemical composition of biogas. The paper presents the characteristics of the biomass subjected to anaerobic processing. Also selected technologies of biogas production from different origin – sewage treatment plants, landfill and agricultural are discussed.