In this study, the energy consumption and the operation cost of using the H2O2/UV process to treat wastewater from the color filter (CF) fabrication were evaluated by the electrical energy per order (EEO). The results showed that both decolorization and mineralization followed the pseudo-first-order reaction. For the UV power of 13 W, as the H2O2 dose increased from 50 to 150 mg/L, EEO reduced from 26.5 to 12.8 kW h m−3 order−1 for total organic carbon (TOC) and from 11.3 to 5.7 kW h m−3 order−1 for color. That is, by increasing the amount of H2O2, the electrical energy efficiency became better due to faster reaction as shown by the larger reaction constant k. Moreover, the electrical energy efficiency was better for the removal of color than for the removal of TOC as EEO,TOC > EEO,color. Moreover, irrespective of TOC and color removals, the EEO values for both UV intensities of 13 and 9 W were close to each other, implying that a higher intensity could be applied by saving the operation time. Through the obtained EEO, the achievable optimum costs to treat CF wastewater for reuse were 0.713 US$/m3 for decolorization and 1.214 US$/m3 for mineralization.