Ultra fine composite metal particles, characterized in that core metal particles which are prepared from a metal salt, a metal oxide or a metal hydroxide and have a particle diameter of 1 to 100 nm are coated with an organic compound having a functional group having chemical adsorptivity to the surface of the core metal; a method for producing the ultra fine composite metal particles; and a device utilizing the metal particles. The ultra fine composite metal particles are excellent particularly in dispersion stability and also can be produced on a commercial scale.
