The invention relates to an implantable capsule, particularly an autonomous capsule of cardiac stimulation, comprising a tubular body provided at the distal end of an anchoring element with a helical screw adapted to penetrate tissue a wall of an organ of a patient, the body housing a set of functional elements of the capsule. It comprises an annular support integral with the body and coaxial therewith, said support surrounding the base of the anchoring element and comprising a series of openings radially extending. The base of the anchoring element comprises a series of rods or tubes projecting in a generally radial direction, and engaged in said openings to thereby secure the anchoring element to the support.