Unfortunately the important characteristics aren't visible here, so it is not possible to determine which species in the Subgenus Smaragdula it could be.
There are two species known to Austria: the Agapanthia intermedia and Agapanthia violacea.
The A. intermedia has longer hairs on the end of the elytras, but more importantly has white hairs on the side of the body between the middle pair and hind pair of legs. See also this image: Side View of A. intermedia.
That is why it is always important to photograph this beetle from the side. (Ventral view)
Due to the lack of white hair on the forehead, cheeks and base of the mandible this is most likely the A. violacea.