PURPOSE: To obtain a brazing backing device of light weight and by which workability for brazing work can be improved and also, cooling efficiency can be improved and easy to form in a panel abutting plane with surface shape fitted in that of a brazing part.

CONSTITUTION: This device is constituted in the brazing backing device 1 in which a brazing nozzle guide die 2 equipped with the panel abutting plane 2a to be abutted with one plane of a metallic panel M in the periphery except for the brazing part of the metallic panel and a brazing nozzle guide part 2b and a back plane side abutting die 3 equipped with a panel abutting plane 3a to be abutted with the brazing part of the metallic panel M and the back plane of the metallic panel in the periphery are connected to each other in such a way that they can be turned. The brazing nozzle guide die 2 and the back plane abutting die 3 are formed with a sintered compact, and surface layer parts 2d, 3d which form the panel abutting planes 2a, 3a to be abutted with the metallic panel M are formed with a material consisting of a sintered compact with denseness of non-water passing property and also, main body parts 2e, 3e are formed with a porous sintered compact of water passing property.