PURPOSE: To enable uniform coating by pressing mixture of liquid and gas to be coated, passing it in a rotary cylinder having many small holes, and oozing it uniformly.

CONSTITUTION: An inner cylinder 1 has the size big enough to form a temporary accumulating chamber for mixture, and many small through holes 4 are formed uniformly on the periphery. Shaft pipes 5 are inserted into the inner cylinder from both sides and both ends of the inner cylinder 1 are supported by bearings 6 to allow rotation around the multiple spindle pipes 5. An outer cylinder 9 is formed of a porous material such as sponge, felt etc. and covers outer periphery of the inner cylinder 1. Oil mixed with air coming out from small holes of the inner cylinder 1 is oozed uniformly from the outer periphery. Supporting vertical rods 10 are provided on both sides of a coating roll A. The outer cylinder 9 is replaceable.