METHOD OF SUBSTITUTING LIGANDS

First ligands coordinated to nanoparticles are replaced by monodentate second ligands that, when coordinated to the nanoparticles, render the nanoparticles non-dispersible in a solvent, and the nanoparticles to which the second ligands are coordinated are separated out as a first solid content by solid-liquid separation. Thereafter, the second ligands are replaced by desirable target ligands by adding, to the first solid content, a second ligand solution containing the target ligands and a third organic solvent.