This is a so called Hurdy Gurdy, an instrument from medieval Europe.
It's a string-based instrument, with a wheel strumming the strings, and the keys tapping the strings for certain notes.
My instrument was built by german instrument-maker Helmut Seibert, it's the model "Pilgerleier" made from mahagony wood.
I'm currently learning to play, although I'm not very good at it yet.