The present invention relates to an improved glenoid anchor for a shoulder joint prosthesis, in particular a convertible prosthesis, of the type intended to be fixed to a glenoid cavity of a shoulder blade and comprising: a structurally independent pin (2), with an internally hollow and essentially thimble-like conical sleeve (12), which has a tapered distal end (3) and an open proximal end (4)； an annular recess (15, 55) formed inside an internal cavity (13) of the pin (2), for receiving by means of mechanical interference a lug (30) of a prosthesis component (9, 9', 9"), substantially locking the lug (30) inside the internal cavity (13)； the outer surface of the sleeve (12) of the pin (2) having an irregular or trabecular structure for favouring osteogenesis and bone integration.
