The present invention relates to the development of a monoclonal antibody which has binding activity to many high-risk types of HPV, etc. The present invention also provides a simple and high-throughput method for measuring cross-neutralizing antibody titers, which is used for assay of cross-neutralizing antibody against HPV in serum samples from subjects, etc. The method of the present invention for measuring cross-neutralizing antibody titers comprises the steps of: preparing a monoclonal antibody against a peptide having a specific amino acid sequence common to high-risk types of HPV and assaying cross-neutralizing antibody using this monoclonal antibody.
