A multi-walled steel pipe consists of at least two pipe bodies of different diameters, and they are overlapped each other. There should be a rough surface: either the inner surface of the outer pipe body or the outer surface of the inner pipe body is. This rough surface has a roughness of 10 to 30 um and is made by etching, or brushing or by using rolls. In addition, in order that the overlapping surfaces can be brazed together, we should plate the overlapping surfaces with copper. And this multi-walled stainless steel pipe bodies are double-walled stainless, seamless and stainless.