An object of the present invention is to improve the reliability of a retaining function by a locking lance without reducing a guiding function of a guiding slant. A locking projection 18 projecting from a cantilever-shaped locking lance 16 extending forward along an inner wall of a cavity 11 includes a first locking area 18a and a second locking area 18b. The first locking area 18a is arranged at a projecting end side of the locking projection 18 and is engaged with a terminal fitting 30 in a state where the locking lance 16 is not resiliently deformed. The second locking area 18b is arranged at a base end side of the locking projection 18 and is not engaged with the terminal fitting 30 in the state where the locking lance 16 is not resiliently deformed, but engaged with the terminal fitting 30 by the resilient deformation of the locking lance toward the cavity.