The UV-H2O2 technique, which is commonly known as a method of decomposing organic substances from wastewater, was applied into cleaning of a stainless steel surface fouled with protein. On a stainless steel surface fouled with bovine beta -lactoglobulin (beta -Lg), H2O2 Solution was made to now, and UV rays were irradiated over the flowing liquid. The amounts of beta -Lg adsorbed before and during the UV-H2O2 cleaning were measured by a reflection absorption technique using Fourier transform infrared spectroscopy (RA-IR). The adsorbed amount approximately decreased linearly with time during the UV-H2O2 cleaning. There was an optimum H2O2 concentration for the removal rate. The H2O2 concentration dependency of the removal rate could be explained by considering the formation and disappearance rates of hydroxyl radicals (. OH), the decay of UV illuminance along the depth of the flow, and the rate of reaction between adsorbed beta -Lg and -OH.