Higgs Boson Sensitivity in ATLAS

Higgs boson searches are one of the main goals of the ATLAS physics program. Higgs boson exclusion limits expected, with an integrated luminosity 1 fb-1 in proton-proton collisions at the centre of mass 7 TeV, are shown. This integrated luminosity can be reached by the end of year 2011 according to the LHC plans. The expected sensitivity for both, the Standard Model Higgs boson and the MSSM Higgs bosons, is discussed. The results are based on the Monte Carlo simulations rescaled from 14/10 TeV studies. Extraction of the background to the H -> W +W - channel from real data is also shown.