In this paper there is proposed an environmentally friendly and energy efficient technology of anaerobic digestion of sanitary sewage water sludges with division of all the process into four consecutive phases: hydrolysis, acetogenesis, acidogenesis and methanogenesis. According to the proposition, each phase takes place in a separate isolated capacity. Optimal values of some parameters of the medium are defined for the process intensification at the each phase. These parameter's values allow activating groups of bacteria, acting on the each phase. As a result, it allows to shorten duration of the digestion and to improve environmental characteristics of digested sludges. The new technology also allows increasing biogas yield during the process. In addition it allows to increase methane content in the biogas and to obtain carbon dioxide separately.