Standard Model Higgs boson searches in pp collisions at sqrt(s)=7 TeV with the ATLAS detector.

We report on searches for the Standard Model Higgs boson with the ATLAS detector at the LHC. Several production mechanisms and decay channels are considered and a wide range of hypothetical Higgs boson masses explored. The datasets correspo nd to integrated luminosities ranging from 4.6 fb-1 to 4.9 fb-1 of pro ton-proton collisions collected at sqrt(s) = 7 TeV in 2011. At the 95% confi dence level the excluded Higgs boson mass ranges are 111.4 GeV to 116.6 GeV, 119 .4 GeV to 122.1 GeV, and 129.2 GeV to 541 GeV, while the mass range from 120 GeV to 560 GeV is expected to be excluded in the absence of a signal. An excess of events is observed at a Higgs boson mass around 126 GeV with a local significanc e of 2.9sigma. The global probability for the background to produce an excess at least as significant anywhere in the mass range explored corresponds to a si gnificance of approximately 1sigma.