There are high demands for inspecting way of bare Si wafer working surface in several tens ran scales with progressing of nanoscale processing technology to detect fine defects. However, it is difficult to find nanoscale particulate defects by conventional methods which are based on scattered light's intensity from defects because its intensity is extremely weak when defects are very small. Then, we conduct research for novel inspecting method of fine particulate defects by using liquid probe system. It uses volatile and inactive liquid for probe capturing automatically plural defects simultaneously by applying property of liquid which build conical film around particles on Si wafer surface with its evaporation. By observing optical multiple interference by these liquid film, it is enabled to detect nanoscale defects optically. In this report, we simulated the optical response and conducted basic experiment to verify our proposed concept and showed possibility of finding fine particulate defects on Si wafer surface.