A surgical bone milling instrument, for operating in a hole formed in a bone, comprising a milling element (10) having a longitudinal axis (A) and a forward portion rotating around an axis (A) for milling bone. The instrument comprises an elongate probe element (20) located internally of and being coaxial with a milling element (10), and sliding longitudinally through the milling element (19), with a forward portion projecting relative to a forward portion of the milling element (10). Means are provided for axially pushing the probe element (20), with the forward portion thereof being made to project beyond the forward portion of the milling element (10). With the invention it is possible to complete the milling procedure of a bone hole, maintaining control of the position of the device relative to the hole. The action of the probe element enables an operator to perceive, also visually, the moment in which the milling head of the instrument reaches the end of a previously-formed hole, or the end of the cavity excavated by the milling head. Operations of further axial advance of the milling head can be monitored with the probe element. Furthermore, by way of axial pressure applied to the probe element, the detachment of the residual bone wall can be achieved as soon as this has reached a breaking resistance lower than the force applied by the probe element.
