The purpose of the present invention is to provide an antibody exhibiting antagonistic action against IL-33, in particular, an isolated human anti-IL-33 neutralizing monoclonal antibody or fragment thereof in which the amino acid sequences of framework regions are germline amino acid sequences or amino acid sequences of combinations of said germline amino acid sequences. Accordingly, epitopes are identified for a plurality of anti-IL-33 monoclonal antibodies, human anti-IL-33 neutralizing monoclonal antibodies are obtained, and mutations are introduced into complementarity determining regions of the human anti-IL-33 neutralizing monoclonal antibodies to specify a complementarity determining region exhibiting high affinity to IL-33. The specified complementarity determining region is used to obtain a human anti-IL-33 neutralizing monoclonal antibody in which the amino acid sequences of framework regions are germline amino acid sequences or amino acid sequences of combinations of said germline amino acid sequences.
