Air sucked together with soiled particles travels along the tube into the vacuum cleaner container filled with water. The dirt stays in the water, and special double hemispheric ribs on the separator whirl the air flow one more time and press it again into the water to be cleaned one more time. Then the sucked air goes up through a spiral-shaped separator, while possible insoluble particles stay in the micro filter. Air filtered in such a way is thoroughly and naturally purified.