An object of the present invention is to provide a molten glass conduit structure with a low stress load even when molten glass is allowed to flow for a long period of time in a double-pipe structure where an inner tube and an outer tube are joined. The present invention has a double tube structure including an inner tube and an outer tube, and a support rib is provided between the inner tube and the outer tube, and the support rib extends in the length direction of the inner tube on the outer surface of the inner tube. The inner straight portion joined along the inner tube, the outer straight portion joined along the length of the outer tube to the inner surface of the outer tube, and the inner straight portion and the outer straight portion extending integrally therewith A connecting wall portion formed, wherein one side edge of the connecting wall portion located between one side end portion of the inner straight portion and one side end portion of the outer straight portion, and the other of the inner straight portion On the other side edge of the connecting wall part located between the side end part and the other side end part of the outer straight part, a recess reaching the end part of both straight parts is formed, and both ends of the inner straight part and the outer straight part Protrusions are formed at both ends.
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