To provide a thin measuring tube body having a meandering passage with a uniform cross section of flow passage, and its forming method.

An extruded tube 2 has at least a pair of pores 4 which are opened at both end faces is formed and, to communicate the pores in the extruded tube 2, a communicating part 6 for communicating a pair of the pores 4, 4 is formed on a parting 5 between these pores 4, 4 by cutting the prescribed length from one end face toward the other end face on the longitudinal direction. By forming a header 3 for clogging the opening 8 in the communicating part of the extruded pipe 2 shorter than the length in the axial direction of the communicating part by a prescribed length, inserting this header into the side of the end face of the communicating part 6 and fixing it, the inexpensive thin meandering tube body having a meandering passage with a uniform cross section of flow passage is obtained.