A resin joint 20 includes an outer cylinder 21 molded by a resin material capable of transmitting laser light and an inner cylinder 22 disposed facing the inner peripheral surface of the outer cylinder 21. An annular protrusion 22b that protrudes in the radial direction and extends in the circumferential direction is formed on the inner peripheral surface of the outer cylinder 21 or the outer peripheral surface of the inner cylinder 22. The axial end of the resin tube 10 is inserted into an annular space 30 and is deformed in the radial direction following the annular protrusion 22b, and a region deformed in the radial direction has a surface that is in contact with the inner peripheral surface of the outer cylinder 21. The inner peripheral surface of the outer cylinder 21 and the outer peripheral surface of the resin tube 10 are laser-welded.