To enhance of the performance of a microorganism carrier 2 and to supply a culture solution 8 with the lowering of a circulation amount and activity of while reducing the load of a blower 15 for a raw gas, in the biological deodorizing equipment of a deodorizing tower 6.

The deodorizing tower 6 is constituted so that the microorganism carrier 2 is provided to the intermediate part in the tower body 1 and a microorganism culture solution shower nozzle 3 is arranged above the carrier 2 and an exhaust cylinder 4 is provided above the shower nozzle 3 while a raw offensive small gas blow cylinder 5 is connected to the tower body 1 under the carrier 2. A microorganism culture solution tank 7 is provided to the bottom part of the tower body 1 to be connected to the shower nozzle 3 by piping 9, and a circulating pump 10 is provided to the piping 9 to circulate the culture solution 8, and a replenishing tank 11 for the culture solution 8 is provided outside the deodorizing tower 6, and the culture solution 8 is intermittently sprayed 12 on the upper part of the carrier 2 from the tank 11. The carrier 2 comprises a void mat 14 formed by entangling curved elastic fibers 13 made of a synthetic resin.