The ICARUS detector. Past, present and future

ICARUS T600 is currently the largest LAr TPC built as a neutrino detector. During its operation in the underground LNGS laboratory, it has recorded events from the CERN to Gran Sasso neutrino beam and cosmic rays interactions. Thanks to its excellent imaging capabilities and very good calorimetric and spatial resolutions, several meaningful results have been achieved. This paper introduces shortly the observation of a free electron lifetime exceeding 15 ms, the identification of atmospheric neutrino interactions and the search of LSND-related anomalies in the νe appearance from the νµ CNGS beam. The LSND anomaly will be further addressed by the Short Baseline Neutrino programme, carried out at the Fermilab laboratory. The ICARUS detector will be used as a far detector in this programme.