To provide a fixing structure of a height detection rod capable of easily attaching the detection rod to a vehicle.

A height detection rod is disposed on a vehicle 1 to which a container filled with a high-pressure gas is fixed. A first fixing portion 10 to the inner side of which a base end 20a of the height detection rod 20 is inserted is fixed to the vehicle 1. Since a protrusion 14 is formed on the first fixing portion 10 in a direction crossing an axis of the first fixing portion, an outer peripheral surface of the base end 20a facing the projection is pressed by the protrusion 14 when the base end 20a of the height detection rod 20 is inserted into the first fixing portion 10. Since the height detection rod 20 is fixed to the first fixing portion 10 by a friction between the base end 20a and the protrusion 14 or the like by inserting, not by screwing, the height detection rod 20 into the first fixing portion 10, the height detection rod 20 can be easily attached to the vehicle 1.