To provide a method for forming nanometal particles where the variation in the particle diameters of metal particles is reduced, and also, the control of the particle diameters is facilitated, and to provide a method for forming nanoorder wiring.

When a metallic material is vacuum-deposited on a substrate composed of a material having nanoorder flatness, and whose surface has extremely reduced chemical bonds, in a state where the substrate is heated to a temperature in the range from 400C to less than the melting point of the metallic material in the vacuum vapor deposition atmosphere, the amount of the metallic material to be vapor-deposited is controlled in a nanoorder, and vapor deposition is caused, so as to form nanometal particles or nanoorder wiring whose diameters are controlled.