PURPOSE: To perform soldering on the site simply in brazing metallic plate by forming a brazing plated layer at the joining part beforehand.

CONSTITUTION: In brazing metallic plates 1, 1, the seam part 18 of the metallic plates to be joined is plated beforehand with the brazing material. On the site, press- contacting is made from both sides of the seam part of the two plates with heating rollers 19, 19, and the metallic plates 1, 1 are brazed by melting the plated layer of the seam part through resistance heating the seam part 18 by applying voltage of 2W10V between the two rollers. Then, the brazed part is cooled by a cooling rollers 20 to complete brazing of the two metallic plate 1, 1. In case when a metallic plate 1' with a recess part is to be soldered to a pipe 14', brazing can be executed in the same manner as above-mentioned, forming a brazing metal plated layer on the joining surface of the two plates, and using the 1st and 2nd heating rollers 23, 21 and the cooling roller 22.