The Institute of Atmospheric Physics investigates the physics and chemistry of the global atmosphere from the Earth's surface up to the upper boundary of the middle atmosphere at about 120 km height. As an institute of the German Aerospace Center (DLR) it answers questions associated with atmospheric processes and with relevance to the research programmes "Aeronautics, Space, and Transportation" and "Energy" of the Helmholtz Association. The institute covers a full variety of methods comprising the development of sensors, observations on different spatial scales (local to global), analysis, theory construction, and numerical modelling including predictability. With these competences the institute works both on fundamental and application oriented problems, where long-term basic research in the forerun of applications is emphasized. The institute offers its competence to the society and the politics in relation to all problems of atmospheric relevance.