The present invention relates to novel antibodies capable of binding specifically to the human insulin-like growth factor I receptor (IGF-IR). The invention likewise comprises the use of these antibodies as a medicament for the prophylactic and/or therapeutic treatment of cancers overexpressing IGF-IR, stimulated either by IGF1 and/or IGF2, or any pathology connected with the overexpression of said receptor as well as in processes or kits for diagnosis of illnesses connected with the overexpression of the IGF-IR and/or the IGF-I/Insulin hybrid receptor.