Tau leptons play a fundamental role in the physics program of experiments at the LHC, since they are an important signature of Higgs boson production and SUSY. The Standard Model processes W → τν and Z → ττ are standard candles for the assessment of the detector performance in identifying hadronically decaying tau leptons. The Z → ττ cross-section was measured at ATLAS in pp collisions at √s = 7TeV with the data sample collected in 2010, corresponding to 36 pb−1, demonstrating the capabilities of ATLAS to perform measurements in tau channels. The measurement in the semileptonic channel is presented
