Provided is a cyclic peptide, which is represented by Formula (I) or Formula (I') and has excellent antibody binding properties and improved chemical resistance, an affinity chromatography support, a labeled antibody, an antibody drug conjugate, and a pharmaceutical preparation. RN-Xg-[Xi-Xa-Xm-X1-X2-X3-Xn-Xb-Xj]k-Xh-RC ··· (I)In Formula (I), Xa and Xb each independently represent an amino acid residue derived from an amino acid, other than L-cysteine and D-cysteine, having a thiol group on a side chain and are bonded to each other through a disulfide bond, or, one of Xa and Xb represents an amino acid residue derived from an amino acid, other than L-cysteine and D-cysteine, having a thiol group on a side chain and the other represents an amino acid residue derived from an amino acid having a haloacetyl group on a side chain, and Xa and Xb are bonded to each other through a thioether bond. RN-Xg-[Xi-Xa-Xm-X1-X2-X3-Xn-Xb-Xj]k-Xh-RC ··· (I')In Formula (I'), one of Xa and Xb represents an amino acid residue derived from L-cysteine or D-cysteine and the other represents an amino acid residue derived from an amino acid having a haloacetyl group on a side chain, and Xa and Xb are bonded to each other through a thioether bond, or, one of Xa and Xb represents an amino acid residue derived from L-penicillamine or D-penicillamine and the other represents an amino acid residue derived from an amino acid having a haloacetyl group on a side chain, and Xa and Xb are bonded to each other through a thioether bond.
