The present invention relates to an anti-MUC1 antibody binding specifically to Mucin 1 (MUC1) and a use thereof and, more particularly, to an anti-MUC1 antibody or an antigen-binding fragment thereof, an antibody-drug conjugate or bispecific antibody comprising the antibody or an antigen-binding fragment thereof, a pharmaceutical composition for prevention or treatment of cancer, comprising the same conjugate or bispecific antibody, and a nucleic acid encoding the same antibody or an antigen-binding fragment thereof, a vector and a host cell, both carrying the same nucleic acid, and a method for preparing an anti-MUC1 antibody or an antigen-binding fragment thereof, using the same vector and host cell. According to the present invention, an antibody binding specifically to MUC1 or an antigen-binding fragment thereof shows outstanding affinity and binding force to MUC1 and an antibody-drug conjugate in which the antibody or an antigen-binding fragment thereof is conjugated with a drug can bind specifically to a MUC1-expressing cell to specifically or selectively transfer the drug with efficacy. Therefore, the anti-MUC1 antibody and the antibody-drug conjugate according to the present invention can be usefully applied to the treatment of a MUC1-related disease, for example, cancer.
