A connector assembly is provided with an electric wire-side housing (51) to be fit on a device-side connector (10) that has relay terminals (20). Guide projections (58) project out from an outer peripheral surface of a wire-deriving tube (52) of the wire-side housing (51). The guide projections (58) guide a shielding tube (71) of a shielding shell (70) in position with respect to the wire-deriving tube (52). Therefore in fixing the shielding shell (70) to a connector-mounting member (40), an inner peripheral surface of the shielding tube (71) contacts the guide projections (58) of the wire-side housing (51) to fit the shielding shell (70) on the wire-side housing (51) without dislocation.