Abstract: This invention provides a peptide that comprises an amino acid sequence consisting of 14 to 18 amino acid residues represented by Formula (I) and is capable of binding to human IgA: (SEQ?ID?NO:?1) H-(X1)-V-C-L-S-Y-R-(X2)-(X3)-G-(X4)-P-(X5)-C- (X6)-(X7)-(X8)(I) wherein each X is independently selected from among the following: X1 represents a Gln residue or a Met residue; X2 and X3 each independently represent an arbitrary amino acid residue other than Cys or either or both thereof are deleted; X4 represents an Arg residue or a Gln residue; X5 represents a Val residue or a Thr residue; X6 represents a Phe residue or a Tyr residue; X7 represents a Ser residue or is null; and X8 represents a Leu residue, a Thr residue, or is null, provided that, when X1 represents a Met residue, X7 represents a Ser residue or is null, and X8 is null. The invention also provides a method for purifying or analyzing human IgA using such peptide.