The present invention relates to an antibody drug conjugate using a bispecific antibody and its use. The antibody drug conjugate of the present invention can easily form a conjugate of an antibody and a drug without a multistep synthetic process though binding of a conjugate of a bivalent cotinine-peptide and a drug, and an anti-cotinine single chain variable fragment. In addition, the antibody drug conjugate can effectively deliver a drug to a target to which the antibody binds specifically, and can enhance a half-life of a drug in the body, thereby improving a therapeutic effect.
