The objective of this work is to study the improvement of etching characteristics in wet etching process. The etching characteristics such as etching factor were investigated under different etching conditions and compared with the spray characteristics. The spray characteristics of nozzle with different geometries such as swirler angle and swirl chamber aspect ratio were analyzed by using PDA system to predict the effect of the spray characteristics on the etching factor. The swirler angles were 49,5$^{circ}$, 63$^{circ}$ and 76.5$^{circ}$. The swirl chamber aspect ratios were 1.2, 1.6 and 2.0. It was found that the etching factor was correlated with the spray characteristics and also the smaller swiller angle, the larger etching factor became.