Abstract: A binding molecule that binds to a binding target substance is selected by introducing an affinity linker into the target binding substance and capturing the substance with a binding partner that binds to the affinity linker. For example, an antibody that binds to an influenza virus antigen can be easily concentrated by labeling a sugar chain present in the antigen with an affinity linker, such as biotin, and then recovering the antigen by binding them to streptavidin. The method for selecting binding molecules of the present invention is also useful in the screening of neutralizing substances.