PROBLEM TO BE SOLVED: To provide a soldering device which can obtain a high-temperature environment and a favorable inert gas environment necessary for soldering while suppressing the running cost of the device.SOLUTION: A soldering device comprises: a power generation part for generating power using supplied fuel and discharging an exhaust gas; an inert gas supply part for supplying at least a part of the exhaust gas to the circumference of a matter to be heated as an inert gas; and a heater for generating power containing the power supplied from the power generation part, heating the exhaust gas supplied to the circumference of the matter to be heated, and heating the matter to be heated via at least the exhaust gas. In the device, a favorable inert gas environment and a high-temperature environment necessary for soldering is obtained by the power and the exhaust gas from the power generation part which is supplied with fuel. Here, it is preferable that the power generation part comprises an internal combus
