The oxide film formed on an indium electrode immersed in a sodium borate (Na2B4O7) solution is influenced by the solution’s concentration, pH, and temperature, as revealed by open-circuit potential (OCP) and polarization techniques. The rate of oxide film growth decreases with increasing pH and rising solution temperature. In this study, we employed Taguchi’s design of experiments (DOE) to minimize the number of experimental trials while identifying the optimal conditions for reducing indium corrosion. The primary objective was to lower the corrosion rate (CR) by optimizing process parameters using the “smaller is better” approach for the signal-to- noise (S/N) ratio. This optimization was based on CR values derived from OCP and potentiodynamic polarization data. An L25 (5 ) orthogonal array (OA) was used to evaluate three key factors: Na2B4O7 concentration, pH, and solution temperature. The optimal factor combination was determined to be (A1 B2 C1), corresponding to a Na2B4O7 concentration of 0.100 ± 0.05 mol/L, a pH of 10.51 ± 0.002, and a solution temperature of 15 ± 0.4 3 C. These conditions were identified as the most effective for minimizing CR of indium under the studied conditions. �