The set comprises a totally implantable device (1) for electroneuromodulation for the electric stimulation of the nervous tissue of the wall of the stomach and/or another neuroreceptive biological tissue and an implantation tool (2) of the device (1), the tool (2) comprising an axially hollow longitudinal containment body (6) for said device (1) and a needle (12) incorporated into said containment body (6) and having a tip (13) that projects forwards to a sharp front end (7) of the containment body (6), said needle (12) being connected to a supply conduit (15) of a fluid injectable from said needle (12) into the tissue for the creation of a localized tissue swelling (4) in which said device (1) can be positioned.