A method of manufacturing a support body for run flat, wherein in a case where the circumferential wall of a tubular blank B is pressingly held between inner and outer molding rollers 1 and 2 and where the molding rollers 1 and 2 are rotated to form at least one circumferentially continuous protruding part on the circumferential wall of the tubular blank B to process the tubular blank B into an annular shell, a molding roller having the maximum outer diameter that is substantially the same as the inner diameter of the tubular blank B is used as the inner molding roller 1.