【Task】 Provided is a purification column containing a porous fiber having excellent removal performance of a substance to be removed and a bundle of the fiber as an adsorption material. SOLUTION: A porous fiber having pores and one or more protrusions on the outer peripheral portion, and satisfying the following requirements (A) to (D). (A) When the pore diameter distribution of the pores is 1.0 or more and 2.8 or less (B), where the diameter of the inscribed circle is Di and the diameter of the circumscribed circle is Do, the degree of deformation Do / Di is 1.35 or more (C) The pore volume of the pores is 0.20 cm 3 / g or more (D) The aperture ratio ratio X represented by the following formula is 6.0 or less (formula). Ratio X = Surface aperture ratio of convex part / Surface aperture ratio of concave part [Selection drawing] None【課題】 除去対象物質の除去性能に優れた、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。【解決手段】 細孔と、外周部に１以上の突起を有し、以下（Ａ）～（Ｄ）の要件を満たす、多孔質繊維。（Ａ）前記細孔の細孔径分布度が、１．０以上、２．８以下（Ｂ）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１．３５以上（Ｃ）前記細孔の細孔体積が、０．２０ｃｍ３／ｇ以上（Ｄ）次の式で表される開口率比Ｘが、６．０以下（式）開口率比Ｘ＝凸部の表面開口率／凹部の表面開口率【選択図】なし
