To provide a sewage cleaning device to remarkably improve treatment efficiency by increasing a turbulent flow caused by the contact of the sewage with a contact material.

In a sewage purifying device constituted so as to provide an aeration means 6 jetting bubbles 13 in a treating tank 1 and to attach contact materials 10a, 10b, which is formed by mounting many projections 12 on the surface of a string like core material 11 having flexibility, spirally winds the core material 11 to stick and breed microorganisms on the surface and is mounted to a supporting frame provided in the treating tank 1, the adjacent contact materials 10a, 10b are arranged alternately to form reversely the winding direction.