An object of the present invention is to provide a purification column having porous fibers excellent in the ability to remove a substance to be purified and a bundle of the fibers as an adsorbent material. A porous fiber having a shape in which three or more fins continuously exist in the outer peripheral portion of a solid fiber in the longitudinal direction and satisfying the following requirements (a) and (b). (A) In the cross section, when the diameter of the inscribed circle is Di and the diameter of the circumscribed circle is Do, the degree of irregularity Do/Di is 1.2 to 6.6 (b) The specific surface area of pores is 50 m2/g or more. [Selection diagram] Figure 1【課題】 本発明が解決しようとする課題は被浄化物質除去性能に優れた多孔質の繊維および該繊維を束として吸着材料としたものを内蔵した浄化カラムを提供することである。【解決手段】 中実の繊維の外周部に３個以上のフィンが長手方向に連続して存在する形状を有し、以下（ａ）及び（ｂ）の要件を満たす、多孔質繊維。（ａ）横断面において、内接円の直径をＤｉ、外接円の直径をＤｏとすると、 異形度Ｄｏ／Ｄｉが１．２～６．６（ｂ）細孔の比表面積が５０ｍ２／ｇ以上【選択図】図１
