To provide a germicidal treatment tank that can be improved in throughput by enabling the tank to heat medical wastes housed in the tank in a short time, and to provide a medical waste treatment system using the tank.

The germicidal treatment tank 3 is constituted so that steam may be fed into the tank 3 through a plurality of steam feeding ports 37 made through the cylindrical wall 31 of the tank 3 and, at the same time, the inside of the tank 3 may be pressurized in the early stages of heating the medical wastes housed in the tank 3. The medical waste treatment system is constituted of the tank 3, a crusher 1, a pre-treatment storage tank 2, a post-treatment storage tank 4, and a volume reducing machine 5. The medical wastes thrown in the tank 3 are subjected to pressurizing and heating treatment by which the wastes are heated while the wastes are pressurized by feeding steam into the tank 3 and, successively, to pressure reducing and dehydrating treatment by which the wastes are dehydrated while the pressure in the tank 3 is reduced by means of a pressure reducing device 7 communicatively connected to the tank 3.