A pipe joint comprising: a joint main body that has a flow path inside thereof and that comprises a pipe body mounting section on an outer side of which a pipe body having substantially a cylindrical shape is mounted and an external thread section ; a cap nut having an inner circumferential surface including an internal thread section which is screwed to the external thread section of the joint main body ; and a sleeve having substantially a cylindrical shape having an outer diameter capable of coming into sliding contact with the inner circumferential surface of the cap nut , wherein the pipe joint further comprises: an insertion groove which is formed between the pipe body mounting section and the external thread section of the joint main body and in which a distal end of the pipe body is inserted; and an elastic member which is disposed in the insertion groove and which comprises a synthetic resin formed to have substantially a ring shape, the elastic member facing to an end face of a distal end side of the sleeve , and wherein in response to the external thread section of the joint main body and the internal thread section of the cap nut being screwed, the end face of the distal end side of the sleeve comes into contact with one end face of the elastic member in an axial direction thereof to compress the elastic member , and the elastic member presses, with a self-repulsion force, the end face of the distal end side of the sleeve in the axial direction, so that an inner circumferential surface of a proximal end side of the sleeve compresses the pipe body in a radial direction of the pipe body through a reaction force received from a fitting surface of the cap nut , and the elastic member itself compresses the pipe body in the radial direction of the pipe body . a joint main body that has a flow path inside thereof and that comprises a pipe body mounting section on an outer side of which a pipe body having substantially a cylindrical shape is mounted and an external thread section ; a cap nut having an inner circumferential surface including an internal thread section which is screwed to the external thread section of the joint main body ; and a sleeve having substantially a cylindrical shape having an outer diameter capable of coming into sliding contact with the inner circumferential surface of the cap nut , wherein the pipe joint further comprises: an insertion groove which is formed between the pipe body mounting section and the external thread section of the joint main body and in which a distal end of the pipe body is inserted; and an elastic member which is disposed in the insertion groove and which comprises a synthetic resin formed to have substantially a ring shape, the elastic member facing to an end face of a distal end side of the sleeve , and an insertion groove which is formed between the pipe body mounting section and the external thread section of the joint main body and in which a distal end of the pipe body is inserted; and an elastic member which is disposed in the insertion groove and which comprises a synthetic resin formed to have substantially a ring shape, the elastic member facing to an end face of a distal end side of the sleeve , and wherein in response to the external thread section of the joint main body and the internal thread section of the cap nut being screwed, the end face of the distal end side of the sleeve comes into contact with one end face of the elastic member in an axial direction thereof to compress the elastic member , and the elastic member presses, with a self-repulsion force, the end face of the distal end side of the sleeve in the axial direction, so that an inner circumferential surface of a proximal end side of the sleeve compresses the pipe body in a radial direction of the pipe body through a reaction force received from a fitting surface of the cap nut , and the elastic member itself compresses the pipe body in the radial direction of the pipe body . <EOS>