Abstract: A bone drill for medical operations is provided. In the bone drill, there is an elongated drill component), which is manufactured from a superelastic material, and an essentially straight drill-component shield, which is hollow. According to the invention, at the end of the drill-component shield there is a guide arrangement for selecting for the drill component a turning angle relative to the drill-component shield, and once the drill component has run through the guide part, the superelastic properties of its material return it to its original shape and the drill component is then is a position, in which it can be used to drill in the direction of the turning angle.