A connector comprising: a housing formed into a cylindrical shape; a terminal holding body holding a terminal (3A, 3B) fixed to a tip end portion of a cable (2A, 2B) in an axial direction, and disposed inside the housing; a water-proof seal disposed inside the housing so as to face to a base end portion of the terminal holding body in the axial direction, and coming into tightly contact with an inner circumferential face of the housing; and a cap fixed to the housing so as to face to a base end portion of the water-proof seal in the axial direction, and pressing the water-proof seal, the water-proof seal has a seal side through hole (41A, 41B) through which the cable (2A, 2B) passes, and a boss through hole formed in parallel to the seal side through hole (41A, 41B), the cap has a cap side through hole (55A, 55B) through which the cable (2A, 2B) passes at a position corresponding to the seal side through hole (41A, 41B), and one of the terminal holding body and the cap has a boss which is protruded from an opposite face facing to the water-proof seal toward the other of the terminal holding body and the cap, passes through the boss through hole and abuts on the other of the terminal holding body and the cap, characterized in that on an inner circumferential face of the cap side through hole (55A, 55B), a plurality of contact projections (56A, 56B) are projected toward a center in a radial direction of the cap side through hole (55A, 55B) at positions separated at intervals in a circumferential direction of the cap side through hole (55A, 55B), and tip end portions of the plurality of contact projections (56A, 56B) come into contact with an outer circumferential face of the cable (2A, 2B) disposed in the cap side through hole (55A, 55B). a housing formed into a cylindrical shape; a terminal holding body holding a terminal (3A, 3B) fixed to a tip end portion of a cable (2A, 2B) in an axial direction, and disposed inside the housing; a water-proof seal disposed inside the housing so as to face to a base end portion of the terminal holding body in the axial direction, and coming into tightly contact with an inner circumferential face of the housing; and a cap fixed to the housing so as to face to a base end portion of the water-proof seal in the axial direction, and pressing the water-proof seal, the water-proof seal has a seal side through hole (41A, 41B) through which the cable (2A, 2B) passes, and a boss through hole formed in parallel to the seal side through hole (41A, 41B), the cap has a cap side through hole (55A, 55B) through which the cable (2A, 2B) passes at a position corresponding to the seal side through hole (41A, 41B), and one of the terminal holding body and the cap has a boss which is protruded from an opposite face facing to the water-proof seal toward the other of the terminal holding body and the cap, passes through the boss through hole and abuts on the other of the terminal holding body and the cap, characterized in that on an inner circumferential face of the cap side through hole (55A, 55B), a plurality of contact projections (56A, 56B) are projected toward a center in a radial direction of the cap side through hole (55A, 55B) at positions separated at intervals in a circumferential direction of the cap side through hole (55A, 55B), and tip end portions of the plurality of contact projections (56A, 56B) come into contact with an outer circumferential face of the cable (2A, 2B) disposed in the cap side through hole (55A, 55B).