Maybe this is the standard graduation gown and hat combination from a some or other country? Or perhaps it is a doctoral or masters graduation gown as they tend to be rather on the fancy side. Anyway, it looks like some sort of academic gown to me - if you can tell us where the photo came from then we could probably help you further.
You say it is a student former suit - do you mean it is the outfit worn by former students? Then it could be an alumni gown.
I don't know why but it looks Italian to me (perhaps it's the similarity to some of the religious robes worn in the Catholic church).