NOVELTY - The method involves treating surface of metal nano particles with an alkanol amine containing solution. Chloride ion adhered on surfaces of metal nano particles with alkanol amine is removed. The chloride ion adhered on the surfaces of the metal nano particles is substituted into the alkanol amine. A clean solution containing one of ethanolamine, diethanaolamine and triethanolamine is prepared. A mixing solution is prepared by mixing the metal nano particles with the cleaning solution. The particles with alcohol or toluene are cleaned to remove a surfactant on the surfaces of the particles.    USE - Method for treating surface of high-purity metal nano particles i.e. nickel nano particles, utilized as a catalyst for a fuel cell, a hydrogenation catalyst and a substitute catalyst of Platinum in chemical reactions, in multi-layered chip element i.e. multi-layer ceramic capacitor.    ADVANTAGE - The method enables effectively removing chloride ion of 99% or more within relatively short process time, thus significantly improving surface treating processing efficiency. The method enables providing alkanol amine containing cleaning solution to show removal ration of high chloride ion of the metal nano particles only by the surface treatment for a short time of about 30 minutes, thus improving manufacturing process yield of the nano particles. The method enables treating chloride ion impurities that are difficult to be relatively removed with the alkanol amine solution so as to effectively remove the chloride ion impurities, thus obtaining the metal nano particles having high purity.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a metal nano particle.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a multi-layer ceramic capacitor manufactured by using nickel nano particles to which a method for treating surface of metal nano particles is applied.    Multi-layer ceramic capacitor (10)    Dielectric sheets (20)    Predetermined internal electrodes (30)    Laminate (40)    External electrodes (50)