An objective of the present invention is to provide a MUC1 antibody having high specificity to cancer cells. The objective has been achieved by the present inventors who found that a cancer-specific sugar chain can be specifically recognized in MUC1 and a cancer cell expressing MUC1 having such a cancer cell specific sugar chain can be recognized. The present invention provides an antibody, an antigen-binding fragment thereof or a MUC1-binding molecule, having, for example, 40-fold specificity or more for a cancer-associated structure of MUC1 as compared to that of a normal tissue-associated structure of MUC1.
