A heat exchange tube is formed by using a sheet member not clad with a brazing material layer, with bonding regions at which ends of the sheet member are overlapped and brazed by using a brazing material. This structure reduces the extent to which the brazing material becomes dispersed while the heat exchange tube is brazed and the likelihood of dissolution due to erosion, which makes it possible to assure the desired product quality, such as corrosion resistance, even when a tube material with a smaller wall thickness is used.