To provide a method for producing metal single crystal having large dimension.

The method for producing metal single crystal includes a step of bringing the solution of a salt containing the metal into contact with the surface of a tannin layer disposed on an epoxy resin cured layer to precipitate the single crystal of the metal on the surface of the tannin layer. The metal preferably comprises one or more elements selected from a group composed of Au, Ag, Pt, Pd, Co, Ni and Cu. The epoxy resin cured layer is preferably obtained by mixing an epoxy resin and a curing agent and heating the mixture.