We studied the deposition of non-aggregated nickel nanoparticles formed by hydrogen reduction of nickel chloride onto silica microparticles in a tubular furnace reactor for catalysts. To produce the non-aggregated nickel nanoparticles, rapid cooling with a Laval nozzle was applied to nickel particles. The diameter of the particles could be controlled by the concentration of NiCl2 vapor and the flow rate of carrier gas N-2 for NiCl2 vapor. Furthermore, we developed a technique for preventing the sintering of nickel nanoparticles by depositing nickel particles onto silica particles with surfaces softened by high temperatures.