It is intended to disclose an antibody which binds to DLL3 protein. Preferably, the antibody of the present invention recognizes a region from amino acids 216 to 492 in human DLL3 having the amino acid sequence as set forth in SEQ ID NO: 1. The present invention also provides a pharmaceutical composition, for example, an anticancer agent, comprising the antibody of the present invention as an active ingredient. The present invention further discloses a method for diagnosing cancer using the antibody of the present invention and a diagnostic drug for cancer comprising the antibody of the present invention.
