In a solder processing device (A) which includes: a substantially tubular iron tip (5) that can be heated and that is extended vertically; and a solder piece supply portion (2, 6) that supplies a solder piece (Wh) from above into the iron tip (5), and in which the heat of the iron tip (5) is used to melt the solder piece (Wh) such that the molten solder is supplied downward, the supplied solder piece (Wh) is forcefully brought into contact with the inner wall of the iron tip (5). In this way, it is possible to more reliably heat and melt the solder piece (Wh) by use of the heat of the iron tip (5).