The present invention provides for isolated anti-human-HER3 antibodies or fragments thereof. More particularly the present invention provides an isolated monoclonal antibody that specifically binds to the extracellular domain of HER-3 and competes for binding to the extracellular domain of human HER-3 with the antibody produced obtainable from hybridoma deposited as CNCM-I-4486. The antibodies described in the present invention are useful for the treatment of cancer.
