The ATLAS detector: status and performance in Run-II

During the 2013/2014 shutdown of the LHC, the ATLAS detector has been improved. A new silicon pixel detector layer has been installed, and the muon detector coverage has been improved substantially. In addition, nearly all other parts of the detector have also been revised to adapt them to the higher pile-up conditions or make them more robust in general. This talk will describe these improvements, and how they affect the performance of physics objects. The initial results showing the detector performance as obtained from cosmic runs and/or initial beam data will also be shown.