PURPOSE: To improve living condition of microbes, prevent large separation of microbes and enhance the purification efficiency of foul water by turning the frame body comprising spreading multiple cord-form lace-form contact materials between side plates with its lower part being dipped in foul water.

CONSTITUTION: A turning frame body 20 which comprises cord-form lace-form contact materials 1 provided with multiple yarn form bodies in multiple directions between, e.g., hexagonal side plates 12 rotating about a horizontal shaft 13 is dipped at its approximate lower half in the foul water 9 in a storage tank 8 and the horizontal shaft part 13 is revolved at the specified low speed by an operating part 14, thence foul water is flowed in through influent port 15 and is discharged through discharge port 16. As compared to rotary disc system, this makes it possible to increase the amount of depositing microbes, improve their living condition, eliminate large separation in mass form of microbes and enhance the purification efficiency of foul water.