A female housing (20) made of a synthetic resin is formed with cavities (22) for accommodating female terminal fittings (21), and locks (24) engageable with the female terminal fittings (21) to retain them are provided in the cavities (22). Each lock (24) projects from an outer surface (20a, 20b) of the female housing (20) during resilient deformation. A lock arm (40) for holding a mating male connector (M) in a connected state is mounted on the female housing (20). The lock arm (40) is made of metal and includes a press-in portion (42) that can be pressed into press-in grooves (30) of the female housing (20). The lock arm (40) is arranged to face the locks (240) and can be retracted into deformation spaces (330) for the locks (240) during the resilient deformation.