Top Quark Properties

The ATLAS potential for the study of top quark properties and physics beyond the Standard Model in the top sector, is reviewed in this paper. Measurements of the top quark charge, the spin and spin correlations, the Standard Model decay (t->bW), rare top quark decays associated to flavour changing neutral currents (t->qX,X =$\gamma$,Z,g) and $t\bar{t}$ resonances are discussed. The expected sensitivity of the ATLAS experiment is estimated for an integrated luminosity of 1 fb$^{-1}$ at the LHC. For the Standard Model measurements the expected precision is presented. For the tests of physics beyond the Standard Model, the 5 $\sigma$ discovery potential (in the presence of a signal) and the 95% confidence level limit (in the absence of a signal) are given.