A connector includes an outer housing, an inner housing to be engaged with the outer housing, and a sliding member. The sliding member includes a first protrusion formed at the leading end part (+Y side) of a first support arm and protruding inwardly (−X-axis direction) that is at a main-arm side, and a second protrusion formed at the leading end part (+Y side) of a second support arm and protruding inwardly (+X-axis direction) that is at the main-arm side.