A lid member that opens/closes an opening of a receptacle connector has a wiping portion that wipes off adhering moisture by rotating to follow contact disposition surfaces upon insertion of a plug connector. Wiper members for wiping off small quantities of moisture remaining after wiping by the lid member are arranged so as to be movable back and forth in a substantially orthogonal direction to the plug connector insertion direction in front of a groove portion into which a contact portion of the plug connector is fitted. The wiper members are disposed so as to be urged towards the outer circumferential surface of the plug connector by elastic members. When fitting the plug connector, distal-end sides of the wiper members closely contact with the contact disposition surfaces of the plug connector and wipe off residual moisture. Thus, electrolytic corrosion of contacts can be prevented and the contact reliability improved.
