Task A bispecific antibody such as a bispecific antibody and various highly functional bispecific antibodies prepared using an antibody against a new human epidermal growth factor receptor 1 (EGFR), which is different from the antibody 528 .SOLUTION: The variable region (2 L: SEQ ID NO: 2) of the light chain of the anti-human epidermal growth factor receptor 1 antibody 225 and the variable region (2 H: SEQ ID NO: 4) of the heavy chain of the anti-CD3 antibody OKT 3, A bispecific antibody against anti-human epidermal growth factor receptor 1 and CD3, etc., comprising a humanized variable region (OL: SEQ ID NO: 6) and a humanized variable region of H chain (OH: SEQ ID NO: 8).(FIG. 15)【課題】 抗体５２８とは別の新たなヒト上皮細胞成長因子受容体１（EGFR）に対する抗体を用いて作製した、二重特異性抗体及び各種の高機能性二重特異性抗体等の二重特異性抗体を提供すること。【解決手段】 抗ヒト上皮細胞成長因子受容体１抗体２２５のＬ鎖の可変領域（２Ｌ：配列番号２）及びＨ鎖の可変領域（２Ｈ：配列番号４）、並びに、抗ＣＤ３抗体ＯＫＴ３のＬ鎖のヒト型化可変領域（ＯＬ：配列番号６）及びＨ鎖のヒト型化可変領域（ＯＨ：配列番号８）を含む、抗ヒト上皮細胞成長因子受容体１及びＣＤ３に対する二重特異性抗体等。【選択図】図１５
