The invention relates to a machine tool (1), in particular a dental milling machine or mill-turning machine, comprising a spindle (10) for receiving a tool and a working arm (12) for receiving a workpiece and comprising at least one nozzle (14a) attached to the spindle (10), in particular with its outlet direction (R) substantially parallel to the axis of rotation (A) of the spindle (10), characterized in that a deflecting body (16) is attached to the spindle (10) or clamped therein, said deflecting body extending in particular at least partially in front of the nozzle (14a). Further, the invention relates to a method of operating the machine tool (1).