Provided are a filler for affinity chromatography which has excellent alkali resistance, and a method for isolating immunoglobulin. The filler for affinity chromatography is a filler in which a protein represented by the following formula (1) is immobilized on a carrier.R—R2 (1)wherein R represents an amino acid sequence consisting of 4 to 300 amino acid residues containing a region consisting of 4 to 20 contiguous histidine residues； and R2 represents an amino acid sequence capable of binding to immunoglobulin, the amino acid sequence consisting of 50 to 500 amino acid residues containing Z domain of Protein A or a fragment thereof, or a variant thereof, provided that the R binds to C-terminus or N-terminus of the R2.
