To easily, surely and efficiently execute the sepn. operation of a large amt. of mixtures by transporting liquids to the liquid inlet sections of plural vessels capable of housing the liquids and solids to be subjected to liquid-solid extraction at rear stages from the liquid outlet sections having the solid outflow preventing means of the vessels at the rear stages among these plural vessels and agitating the liquid-solid mixtures in the vessels.

A proper amt. of adsorbents 7, such as, for example, the solids and the liquids 8 corresponding t moving layers are put into the respective vessels 3, which are then hermetically closed by caps 3a. When a moving phase soln. is sent at an arbitrary flow rate from the vessel inlet section 1 at a start point while the inside of the vessel 3 is kept agitated, the liquid of the volume corresponding to the liquid volume flowing into the vessel 3 flows out of the liquid outlet section 2 subjected to the outflow prevention of the solid. The mass quantity in the liquid flowing out of the vessel 3 is in a distributed and equilibrated state with respect to the adsorbents 7. Then, the one vessel 3 corresponds, in an ideal case, to one stage of the stage theory of chromatography. If 10 pieces of the vessels 3 are connected, the sepn. system corresponding to the 10 stages of the chromatography is formed and, therefore, the sepn. of a large amt. of samples may be executed with high efficiency.