It is an object of the present invention to provide a novel antibody having a high binding activity and a high neutralizing activity on influenza viruses. The present invention provides an antibody, which neutralizes H1 influenza virus and/or H5 influenza virus, wherein the antibody has a heavy chain variable region having CDRs consisting of a defined heavy chain first complementarity-determining region (VH CDR1), a defined heavy chain second complementarity-determining region (VH CDR2) and a defined heavy chain third complementarity-determining region (VH CDR3), and a light chain variable region having CDRs consisting of a defined light chain second complementarity-determining region (VL CDR2) and a defined light chain third complementarity-determining region (VL CDR3).
