To enhance brazing performance of Mg-containing aluminum alloy, wherein the content of Mg is 0.05 to 1%, when performing brazing in an inert gas atmosphere using a fluoride-based flux.

In the heating process for brazing heating, immediately before starting the melt of brazing filler, vapor containing flux is provided to a material to be brazed. Particularly, the supply of the vapor containing flux to the material is started at such timings that the relationship of the temperature of the material t(C) when feeding the vapor containing flux and the melting start temperature of the brazing filler m(C) satisfies tm-20 (preferably, tm-10).