Provided is a highly sensitive and less expensive lectin-immobilized base material (for example, a lectin plate), such as lectin-immobilized base material having stable qualities and being able to be sufficiently washed after a target sugar chain-containing antigen binds thereto. Further provided is a method for immobilizing lectin to a base material therefor. Particularly provided are: a method whereby a lectin-peptide fusion, in which a peptide capable of adsorbing to a base material surface such as a polystyrene (PS) tag is fused with the N-terminal side or C-terminal side of lectin capable of recognizing a target sugar chain, is immobilized on the peptide side to a base material; and a lectin-immobilized base material produced by this method. By using the lectin-immobilized base material, a target sugar chain-containing antigen can be highly sensitively and evenly measured and, moreover, target sugar chain-containing cells, etc. can be separated (concentrated and harvested).