It is an objective to provide a part-mounting method that, even when parts are extremely small, makes it possible to mount the parts at a repair-requiring location without fail, to thus enhance a percentage of a non-defective substrate. In a part-mounting method, inspection is made as to whether or not a parts-missing location exists on a substrate Pb reloaded between a solder printer 2 and a first part-mounting machine 4A after having undergone manual repair by an operator OP, or the like, in connection with a repair-requiring location found through inspection performed after mounting of parts Pt, by use of an inspection camera 15A of a first part-mounting machine 4A. When a parts-missing location on the substrate Pb is found, the parts-missing location is identified. Subsequently, a mounting head 14A of the first part-mounting machine 4A and a mounting head 14B of a second part-mounting machine 4B mount a part Pt at the parts-missing location on the thus-identified substrate Pb.