A connector is provided with a first housing (10) including a lever 30 rotatably mounted about supporting shaft bearings (34), and a second housing 60 including cam followers (63) engageable with cam grooves 41 of the lever 30 and to be connected with the first housing (10) by a cam action displayed between the cam grooves (41) and the cam followers (63) as the lever (30) is rotated. The second housing (60) includes posture correcting pins (66) at the opposite sides of the cam followers (63). The lever (30) is formed with posture correcting grooves (45) engageable with the posture correcting pins (66) in a rotating process thereof and extending along arcs centered on the supporting shaft bearings (34).