The T600 ICARUS detector, with a mass of about 600 tons of liquid argon (LAr), is the largest LAr Time Projection Chamber (TPC) ever built. It has been successfully tested in Pavia/Italy in 2001. More than 29,000 cosmic rays events have been collected during about 100 days of continuous data taking. It was demonstrated that large mass scale LAr TPC technique is operational. The T600 ICARUS test run results are briefly reported in this paper.

PACS numbers: 29.40.--n, 29.40.Gx