Abstract: The jig is formed based on a three-dimensional reconstruction of the bone elements of the joint from tomodensitometric data; the marking of points on the humerus being used as a basis for the positioning of the considered prosthetic element. The jig includes: a support base cooperating with the humeral head according to a single position, one portion of the base cooperating with the intertubercular sulcus or bicipital groove; a gripping portion; and a breakable area temporarily receiving a cutting block to allow its fixation to the humeral bone before enabling to perform the humeral resection.