An ultraclean wafer surface is crucial for high quality processing in Si technologies. Cleaning of the Si wafer surface has been accomplished by RCA wet cleaning for the past quarter century, where there exists high temperature processes consisting of H2SO4/H2O2/H2O, NH4OH/H2O2/H2O, and HCl/H2O2/H2O treatment. Thus, RCA cleaning requires a large number of processing steps, resulting in the consumption of a huge volume of liquid chemicals and ultrapure water, and simultaneously consuming a large volume of clean air exhaust to suppress chemical vapor from getting into the clean room. Total room temperature wet cleaning consisting of five cleaning steps has been developed for Si wafer surfaces, where consumption volume of liquid chemicals and ultrapure water has been reduced less than 1% and 5%, respectively, compared to that of RCA cleaning. The newly developed cleaning technology has been confirmed to contribute to future simplified and low cost manufacturing of ultralarge scale integrated devices.