A soldering method in which, out of soldering steps of (a) during soldering, (b) before soldering, and (c) after soldering, in at least the steps of (a) during soldering and (b) before soldering, an alternating current whose frequency temporally changes in a band of 20 Hz-1 MHz is applied to at least any of (d) a solder material, (e) a soldering object, and (f) a peripheral portion thereof, and a modulated electromagnetic wave treatment is carried out by use of an electromagnetic field induced by the alternating current. Thereby, when not only a lead-containing solder material but also a lead-free solder material are used, wettability in soldering to a soldering object is made better, and an obtained soldered article is improved in strength, etc., compared to the conventional solder material.