To provide a multihole pipe for heat exchange and its manufacturing method capable of manufacturing easily at low cost.

Two copper plates 20 with grooves 14 formed in a longitudinal direction by rolling a copper plate 11 by a rolling roll 12 are used. Surfaces on the groove 14 side of the copper plates 20 serve as joint surfaces, and a sheet like wax material 21 is sandwiched between the joint surfaces. After positions of the grooves 14 of both of the copper plates 20 are fitted, the copper plates 20 are heated and joined.