The cell growth inhibitor provided by the present invention comprises, as an antibody component, an artificially produced anti-EGFR antibody having specific binding capacity to EGFR which is characterized in that an epitope therefor is in a cysteine-rich subdomain 2 (C2 domain) and/or in a ligand-binding domain 1 (L1 domain) among four subdomains contained in the extracellular domain of EGFR.