I love it!
Beautiful beetle, great photo, incorrect ID.
Though the colors may resemble that of C. externum, this specimen is not only considerably more elongate; the elytra are much less smooth, lacking the punctures in the description; the pronotum clearly does flare apically, which is the opposite condition of the description. Calosoma externum lives in the Midwest and Southeastern states of the USA, this reminds me me of a European specimen. The beautiful colors may vary and are and found in multiple genera of Carabids, as the copied BugBuide description points out, google the species they suggest.
Oh man, after writing all that I see that Radomir has already identified it! Beetles are just too diverse to reliable get a species name from an online image search. Gorgeous insect and nice shot.