Flake-shaped fine particles were modified with a thin TiN layer by a hexagonal-barrel-sputtering technique. To determine the optimum sputtering conditions, TiN films were deposited on a glass substrate by the reactive sputtering technique by varying the values of N 2 percentage, total pressure, radio-frequency (RF) power, and substrate temperature. From the analysis of XRD patterns, it was determined that a N 2 percentage of 25%, a total pressure of 1.2 Pa, a RF power of 200 W, and room temperature were suitable for the preparation of TiN films. Under these optimized conditions, Al flakes were modified with a TiN by the barrel-sputtering technique. The results of optical microscopy, X-ray diffraction measurements, scanning electron microscopy, and energy-dispersive X-ray spectroscopy measurements revealed that the surface of each Al flake was successfully coated uniformly with a TiN layer.