To provide a soldering device which can supply much heat to the part to be soldered so that it can perform the supply of solder securely.

In the soldering device, there is a hollow opened at the tip and equipped with a solder pot at the root so that molten solder is fed to the tip of the iron through the hollow path. Preferably the hollow iron has a cylindrical shape because the supply of heat to the part to be soldered can be increased through the cylindrical shape of the iron tip. Both the soldering iron and the solder pot are held by a robot. A shutter is equipped at the opening of the iron tip which can freely open or shut. It opens during soldering in order to supply molten solder and shuts otherwise to protect molten solder from flowing out.