To provide an air-liquid mixture suction force feeder for optimally controlling the amount of air.

The air-liquid mixture suction force feeder comprises a casing 110, a suction pipe 120, a discharge pipe 180, a high pressure water supply device 130, and an air supply device 140. The casing has an inlet communicating with the suction pipe and an outlet communicating with the discharge pipe. The high pressure water supply device is connected to the casing and the air supply device is also connected to the casing. In this construction, a water column passing through the casing passes through the discharge pipe in an air-liquid mixed condition 190 while inducing air, producing negative pressure in the casing. Treated objects are sucked by negative pressure and associated with the water column, and at the same time they are forcibly fed from the discharge pipe. The air supply device optimally controls the amount of air in an air-liquid mixture passing through the discharge pipe.