Postcard AX-33

Is that a national costume for Åland?

No, this is some sort of gákti (gaeptie, määccaǩ, mááccuh), which are worn by the Sámi (north of Finland, Norway and Sweden as well as nearby areas in Russia). I think it's a real one, but there are lots of fake gákti out there too, worn for tourism purposes, not tradition.