To provide joint structure of a locking rod and a roller unit, reducing cost because of not needing supplementary machining at all and making fitting work rapid in a single action.

In this joint structure, a roller 6 is mounted to the tip part of a unit body 4 by a horizontal shaft 7, and a side face part of the unit body 4 is provided with a vertical groove part 4a into which a locking rod is fitted. The tip part of the vertical groove part 4a is provided with a horizontal hole part 4b into which a tip bent part 3a of the locking rod is fitted, and an inhibiting protuberant part 5 elastically engaged with the peripheral surface of a main body part of the locking rod is provided on the base end inner surface side of the vertical groove part 4a.