  The in-situ commissioning of the ATLAS liquid argon calorimeter is taking
place since three years. During this period, it has been fully tested by means
of frequent calibration runs, and the analysis of the large cosmic muon data
samples and of the few beam splash events that occurred on September 10th,
2008. This has allowed to obtain a stable set of calibration constants for the
first collisions, and to measure the in-situ calorimeter performances that were
found to be at the expected level.
