The present invention relates to a coaxial connector comprising: a body; and a central contact mounted in the body with interposition of insulation; wherein the insulation comprises at least two distinct portions: a) that are separated by an interface presenting at least a fraction that extends obliquely relative to the axis of the connector; and/or b) that are made of different dielectric materials; the connector being configured to withstand breakdown phenomena at altitude, in particular under vacuum conditions.