Increased disk rotational speed of hard disk drive and contamination by nanoparticles can cause serious problems including thermal asperity (TA). In this study, the filtration efficiency of recirculation filter system in the hard disk drive was investigated with various particle contamination locations and disk rotational speeds. In result, the filtration efficiency was clearly affected by the particle-generated location. The filter efficiency of nanoparticles generated at the center side of disk surface was lower than that at the edge side of the disk. For improving the filter efficiency, we added a comb-shape pattern to hard disk clamp and spacer. And improved filter efficiency was observed with various comb angles and disk rotational speeds.