A combined search for the Standard Model Higgs boson with the ATLAS experiment at LHC using datasets corresponding to integrated luminosities from 1.0 to 2.3 fb−1 of pp collisions at √s = 7 TeV is presented. The Higgs boson mass ranges 146 - 230 GeV, 256 - 282 GeV and 296 - 459 GeV are excluded at 95% Confidence Level, while the range 131 - 450 GeV is expected to be excluded in the absence of a signal. Searches in several decay channels are discussed: H → γ γ , H → b ¯ b, H → τ + τ −, H → ZZ ( ∗) → l + l −l ′ +l ′ −, → WW ( ∗) → l ν l ν , H → WW → l ν qq, H → ZZ → l l ν ν , H → ZZ → l l qq. No significant excess was observed in any of these channels for the entire mass range from 110 to 600 GeV. In addition, a search for neutral Higgs bosons in the Minimal Supersymmetric extension to the Standard Model (MSSM) is presented.