HARD QCD Measurements in ATLAS

Proton-Proton collisions at the LHC offer the possibility to study perturbative QCD at unprecedented small distances. Various observables involving jets enable detailed tests of up to date MC generators as well as NLO calculations in a new region of phase space opened by the large centre-of-mass energy. The extension of the kinematic reach for inclusive jet and multijet transverse momentum spectra and for dijet mass spectra was possible already in the initial phase of data taking with a relatively small amount of integrated luminosity due to the large QCD cross section. Apart from tests of the theory of strong interaction itself a detailed understanding of QCD is also important for the interpretation of many searches for new physics where QCD presents often one of the dominant backgrounds. An alternative approach to jet observables offers the study of prompt photon production which is also being investigated with first data. In this talk we present results of various jet measurements, compare them to predictions from MC generators and NLO calculations and show the status of prompt photon measurements.