Status of the ATLAS experiment

The ATLAS Experiment at the CERN Large Hadron Collider was operated with colliding proton beams at 7 TeV center of mass energy since March 2010. It will study a broad range of particle physics at the highest available laboratory energies. At the time of the conference ATLAS, with high data taking efficiency, had integrated a luminosity of few inverse picobarn, which allowed already observation and measurement of Standard Model processes, like vector boson and top production. Detector status, event reconstruction and particle identification performance in this first period of operation are presented together with selected first physics results.