NOVELTY - Method involves feeding sewage water to receiving reservoir; pumping sewage water into aeration tank and further into secondary settler; providing flowing of sewage water from secondary settler into outlet reservoir. In receiving reservoir sewage water is circulated while being exposed to active silt and small-sized bubble aeration of variable intensity. In aeration tank mixture of sewage water and active silt is caused to circulate in vertical-circular path around secondary settler immersed into water. Particles which come to water surface in upper part of secondary settler are caught and water and silt are separated. Method further involves filtering sewage water through mechanical filter comprising long bristles and subjecting water to purification followed by urging water to flow into receiving reservoir wherein water is exposed to additional ozone purification and disinfection; thereafter washing main air lifts and mechanical filter and simultaneously feeding ozonized water into receiving reservoir and aeration tank; providing discharge of clear water under pressure; automatically removing floating particles in upper part of secondary settler into receiving reservoir and excessive active silt from aeration tank zone maximally remote from aeration member into reservoir of active silt aerobic stabilizer from which water containing active silt flows back into aeration tank; removing settled silt after additional oxidation through lower slot of secondary settler and directing it back into active zone of aeration tank. Disinfection and pumping out processes are controlled using level controlling sensor in output reservoir and controller which is started by means of signal delivered from this sensor.    USE - Purification of domestic sewage water by combined biochemical process.    ADVANTAGE - Improved quality, reliable and intensified purification process due to employment of immersed secondary settler in aeration tank, provision for additional steps such as additional oxidation and disinfection, automatic washing of basic components, and also due to employment of control sensor in outlet reservoir.