There is provided a chamber open to the outside through openings through which a solder-adhered object is passed and the chamber having a heating/melting area, a carrying mechanism for carrying the solder-adhered object into the heating/melting area, a formic-acid supplying means for supplying a formic acid into the heating/melting area, an exhausting means for exhausting a gas from the heating/melting area and its neighboring area to create a lower pressure area in the heating/melting area as compared to the pressure of outside the chamber, heating means for heating directly or indirectly the solder-adhered object in the heating/melting area, and an air-stream suppressing means for disturbing a gas flow between the heating/melting area and the carrying areas. Accordingly, there can be provided a solder jointing system for jointing solder layers of a semiconductor device, an electronic device, or the like to the wirings or the pads, which is capable of having a high processing ability and preventing re-oxidation.