To provide a method of manufacturing a metal nanoparticle sintered compact capable of reducing the scattering of a conductivity of the whole sintered compact layer to be formed and at the same time keeping the conductivity of the whole sintered compact layer obtained in a range of 110-5 cm or below with a high reproducibility, when the metal nanoparticle sintered compact is produced by a low temperature sintering of metal nanoparticles.

After applying a dispersion liquid in which metal nanoparticles with an average particle diameter of 1-100 nm, the surface of which is coated with alkylamine, are dispersed in an organic solvent having a boiling point of 100C or higher, the metal nanoparticle sintered compact is formed by efficiently removing alkylamine covering the surface of the metal nanoparticles by heating at a temperature of 100C-200C under pressurized atmosphere of 1.5 atm-10 atm.