An annular contact is enabled to be firmly retained by an insulating housing without affecting the mating force or removing force between there and a matching connector with a simple configuration. Divided end parts of the annular contact attached to the insulating housing are provided with contact retaining parts that abut part of the insulating housing and retain the annular contact at the insulating housing when removal with respect to the matching connector is carried out, so that the shapes and sizes of the contact retaining parts are not affected by elastic force of the annular contact, in other words, mating force or removing force with respect to the matching connector almost at all to facilitate adjustment of the mating force or removing force between there and the matching connector.