A coaxial connector is suitable for being received in an opening in a panel, in particular a wall of a metal box. The connector comprises a conductive tubular body, a conductive tubular grounding plate and at least one resilient member, said grounding plate being movable in translation coaxially relative to said body, said grounding plate having a continuous rigid bearing surface for pressing against said panel, and said at least one resilient member, in particular a spring, being arranged to urge the grounding plate into a given position relative to the tubular body and to press the grounding plate against said panel when the connector is assembled with a complementary connector element.