PURPOSE: To prevent the generation of an uneven phenomenon, a bad odor, mold, etc., by a method wherein both a first partition plate on which a plurality of small holes are formed, and a second partition plate provided under the first partition plate are formed in the title apparatus; and on the first partition plate, a first layer of active carbon is placed, and on the second partition plate, a bioceramic layer is placed and on the bioceramic layer, a second layer of the active carbon is placed.

CONSTITUTION: When a used solvent is sucked from a reservoir for the used solvent by a liquid pump 7, this used solvent is sent to a solvent-spraying part 10 through a feed pipe 9. The used solvent sent to the solvent-spraying part 10 is sprayed at a constant pressure through a plurality of small holes 10a formed on the solvent- spraying part 10, and beats against a first layer 11 of active carbon placed on a first partition plate 2. In this way, foreign materials and waste materials mingled in the used solvent are filtered through the active carbon and absorbed therein. Aside from the first layer 11 of the active carbon, a second layer 16 of the active carbon is placed on a bioceramic layer 14, and thus the foreign materials and waste materials mingled in the used solvent are sufficiently filtered and absorbed. In this way, the generation of an uneven phenomenon, a bad odor, mold, etc., can be prevented.