Searches for a heavy Higgs boson at ATLAS

The experimental results of the search for the Standard Model Higgs boson at the Large Hadron Collider (LHC) running at a centre-of-mass energy of 7~TeV are reported, based on a total integrated luminosity of up to $4.9$~fb$^{-1}$ collected by the ATLAS detector in 2011. Several channels contributing to the sensitivity in the high-mass region above $m_H = 200$~GeV are discussed. Upper limits are derived on the production cross section as a function of the Higgs boson mass. A wide range of Higgs boson mass hypotheses is excluded at a $95\%$ confidence level.