Abstract: Broach sharpening machine in which a slide mobile in a direction transverse to the longitudinal axis of a broach to be sharpened supports a sharpening slide provided with a grinding wheel head, and a feeler unit arranged to determine the position of each broach tooth relative to the grinding wheel and comprising an articulated parallelogram in which a drag link is provided with a coupling element arranged to cooperate with the broach teeth, and is connected by two resilient cranks to a frame so that it rotates with this latter about a horizontal axis perpendicular to the broach axis; the feeler unit comprising a sensor for detecting the movements of the frame about its axis of rotation and the axial movements of said drag link, and a resilient element arranged to rotate said parallelogram so as to move said coupling element towards the broach.