PURPOSE: To enhance the contact of an air containing floated powders and a liquid and separate powders effectively by a mechanism wherein an air containing floated powders is transported into a powder separating tank containing a liquid and powders are separated.

CONSTITUTION: The powder 8 transported into a powder storage tank 5 through a powder supply pipe 6 by air is precipitated to a lower portion of a tank 5 by a buffle plate 7 provided at an upper portion of a tank 5. An air containing floated powders is sent into a powder separating tank 1 containing a liquid 2 therein by a supply pipe 3 and, by opening a leading end of a supply pipe into a liquid 2, powders contained in air is collected by a liquid and purified air is exhausted from an exhaust pipe 4.