To provide a pipe joint capable of coping with a different diameter of holes of a box.

An engagement part 31 engaged with a circumferential edge of a hole 12 in the box 11 is provided continuous to a pipe fitting part 21 with a pipe 13 integrally fitted thereto, and a first cylindrical part 32 fitted in the hole 12 of relatively large diameter in the box 11 is provided continuous to the engagement part 31. A first non-return claw part 34 which is elastically expanded on the opposite side through the hole 12 of the relatively large diameter in the box 11 is cut and erected in the direction facing the engagement part 31 from the outer circumferential surface of the first cylindrical part 32. A second cylindrical part 36 fitted to a hole of relatively small diameter in the box 11 has the diameter smaller than that of the first cylindrical part 32. A second non-return claw part 39 which is elastically expanded on the opposite side through the hole of the relatively small diameter in the box 11 is cut and erected in the direction facing an end face 38 of the first cylindrical part 32 from the outer circumferential surface of the second cylindrical part 36.