To provide an improved compact double pipe joint with a pipe joint (an inner pipe joint) for transferring fluid and an outer pipe joint integrated therewith for protecting a pipe, conveniently adopting a double pipe which has various advantages for transferring fluid.

The double pipe joint is provided for connecting the double pipe H consisting of fluorine tube outer and inner pipes H2, H1. It comprises an inner pipe connection inner joint part T1 consisting of a sleeve 2 to be internally fitted and pressed into an inner pipe end H1t, an inner pipe joint body 1 to be externally fitted thereto, and an inner pipe union nut 5U, and an outer pipe connection outer joint part T2 consisting of a sleeve 4 to be internally fitted and pressed into an outer pipe end H2t, an outer pipe joint body 3 to be externally fitted thereto, and an outer pipe union nut 5S. The outer pipe joint body 3 is threaded to the inner pipe joint body 1 to encircle the inner pipe union nut 5U being threadedly mounted on an inner pipe socket part 8.