PURPOSE: To provide a hollow body that has good use characteristics and can be rapidly laid in certain cases and manufactured with a simple process and at a low cost by improving the hollow body particularly such as a muffler, a filter, a conduit or the like for guiding a fluid to pass through it.

CONSTITUTION: A hollow body composed of a metal outer tube having a substantially oval or a circular cross section over a longitudinal section and made of a metal thin and flat strip 10 rolled up in the form of a spiral with mutually matched outer edges bonded to each other by folded portions is manufactured by forming an outer tube 21 to have a at least two-fold wall structure and spirally rolling up and folding together the same number of entrance strips as the number of the outer tubes and having the same width as that of the outer tubes.