To provide a duct joint capable of being simply and stably mounted in a through hole part formed on a web of a steel frame beam.

This duct joint 10 is composed of a cylindrical joint body 11 in which end parts of a pair of ducts 6, 6 inserted into a through hole 4 formed on the web 3 of the steel frame beam 1 and arranged on both sides across the web 3 are externally fitted and a nipping and holding body 12 provided on the joint body 11 to nip and hold the web 3 from its both sides. The nipping and holding body 12 is provided with a first abutting member 13A being externally fitted and fixed in the joint body 11 and being abutted on a side face on one side of the web 3, a second abutting member 13B being detachably and externally fitted in the joint body 11 and being abutted on a side face on the other side of the web 3, and a pressing member 17 being detachably screw-fitted into the joint body 11 and pressing the second abutting member 13B against the side face on the other side of the web 3.