An object of the present invention is to provide an antibody which does not bind to a normal cell, and is specific for a cancer cell. The object was solved by the finding by the present inventors that an antibody obtained by immunizing an animal using a 2, 3ST glycopeptide as an antigen unexpectedly recognizes a sugar chain specific for a cancer specifically and remarkably, and consequently, can recognize and kill a cancer cell expressing MUC1 having such a cancer cell-specific sugar chain. The present invention provides, for example, an antibody, an antigen-binding fragment thereof or a MUC1-binding molecule, in which specificity for a cancer-associated structure of MUC1 is 100-fold or more as compared with that for a normal tissue-associated structure of MUC1.