IAGOS (In-Service Aircraft for a Global Observing System) is a large-scale European Research Infrastructure (ESFRI) conducting long-term observations of atmospheric composition on a global scale from commercial aircraft of internationally operating airlines. The project CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) is the “flagship project” within IAGOS. 19 fully-automated instruments are being installed in a 1.6 t cargo container, which is designed to fit into a Lufthansa aircraft (Airbus 350-900, Erfurt) with a specially designed inlet system in its fuselage. The instrumentation installed on CARIBIC can measure over 100 trace species in the upper troposphere / lower stratosphere (UTLS) at typical cruising altitudes of ~10-12 km. There are typically 2 return flights per month from Munich to destinations around the globe covering the northern and southern hemisphere. When the aircraft is descending, vertical profiles of atmospheric constituents can also be established. IAGOS-CARIBIC is a worldwide unique platform that fill a very important gap concerning the understanding and monitoring of atmospheric composition associated with climatic change. It complements existing ground-based observatories and space-borne remote sensing missions by providing observations in the UTLS with unique detail and accuracy.