PROBLEM TO BE SOLVED: To provide an anti-human HER3 antibody which is non-competitive and allosteric with respect to neuregulin (NRG), and a pharmaceutical composition containing the antibody.SOLUTION: An anti-human HER3 antibody which is non-competitive and allosteric with respect to neuregulin (NRG) and comprises a heavy chain, where the variable domain comprises H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2 and L-CDR3 each having at least a fixed percentage with respect to a specific sequence, the antibody specifically binding to HER3 with substantially the same affinity as antibodies comprising the specific sequence.SELECTED DRAWING: None