An object of the present invention is to improve the concentration ratio and recovery rate of cells in a method of concentrating cells by passing a cell suspension through a hollow fiber type separation membrane. According to the method for concentrating cells of the present invention, a cell suspension is directed from the bottom to the top in a hollow fiber type separation membrane arranged so as to extend at an angle of 20° to 70° with respect to the horizontal direction. Inflowing at a flow rate of 1 mL/min to 90 mL/min and passing therethrough to concentrate the cell suspension. [Selection diagram] Figure 2【課題】本発明は、細胞懸濁液を中空糸型分離膜内に通過させて細胞を濃縮する方法において細胞の濃縮倍率及び回収率を向上させることを目的とする。【解決手段】本発明の細胞濃縮方法は、水平方向に対し２０°～７０°の角度で延在するように配置された中空糸型分離膜内に下方から上方に向けて細胞懸濁液を１ｍＬ／ｍｉｎ～９０ｍＬ／ｍｉｎの流入速度で流入させ、通過させて、細胞懸濁液を濃縮することを含むことを特徴とする。【選択図】図２
