A substantially tubular iron tip (5) that can be heated and that is extended vertically and a solder piece supply portion that supplies a first solder piece (Wh1) and a second solder piece (Wh2) in which a layer of a flux (72) is provided within a tubular solder layer in this order from above into the iron tip are provided, within the iron tip, the solder pieces are erected such that on the first solder piece, the second solder piece rides and the heat of the iron tip is used to melt the first solder piece and the second solder piece such that the molten solder is supplied downward. In this way, it is possible to more reliably heat and melt the solder pieces in a posture in which they are erected within the iron tip.