Measurement of properties of the top quark with the ATLAS detector at LHC

The top quark is the heaviest elementary particle and the only quark that decays before hadronizing. Properties of the top quark constitute important tests of the Standard Model and constrain models of new physics. Measurements of top quark properties by ATLAS using proton-proton collisions in the LHC at sqrt s = 7 TeV are presented, as well as combinations of results by ATLAS, CMS and the Tevatron. Here the top quark mass, polarization, electric charge, charge asymmetry and the spin correlation in ttbar pairs are discussed. The results are compared to the standard model prediction and to predictions from different models for new physics.