The ATLAS pixel detector is built from 1744 modules which are organized in three barrel layers and three disk layers in forward direction. The modules consist of an oxygen-enriched silicon sensor with an active area of 60.8×16.4mm2. Its 46080 pixels are read out by 16 frontend chips, bump bonded to the sensor using a state-of-the-art hybridization technique. After extensive characterization of the single modules they are mounted on support structures, made from a carbon–carbon composite material, which make up the barrel or the disc layers. The first of these assemblies are used to study the behavior of the modules outside the lab environment.