Hi Cerjak,
This is one of a group of - mostly German made - crossbows for sporting or hunting which, as the gun-like shape of the 'buttstock' (rear end of the tiller) indicates, were made from the late 17th to the mid-18th c. As your sample retains some amount of bone inlay I would suggest a date of late 17th c. It seems to be preserved in good and original condition, apart from the worming. Even the horn bolt clamp seems to be the original.
In case you wish to learn more about earlier crossbows please see my thread
http://www.vikingsword.com/vb/showthread.php?t=7516
Best,
Michael