It is an object to provide a solder iron such that in the solder iron for blowing out a heating gas flow to a periphery of a forward end tip, the heating gas flow having stable temperature is generated. A nozzle section is provided to a forward end tip heated by heating means of a solder iron main body, an orifice section is formed between a heating gas flow generating chamber and the nozzle section, and a back pressure of thermally expanded heating gas and a pressure of gas successively supplied are balanced in the heating gas flow generating chamber.