A functional coating designed to prevent pollution was investigated on the surfaces of cover glass substrates for a photovoltaic (PV) module to improve the cover glass's anti-pollution characteristics. To identify the characteristics that can prevent pollution as well as the change in the contact angle of the thin film on the cover glass surface, three field-applicable coating methods were applied, and the coatings were annealed in two different annealing steps using a furnace. Step 1 refers to the annealing treatment of the coated films at 200 °C while step 2 refers to the second annealing treatment at 200, 300, and 400 °C. The anti-pollution characteristics, contact angle, transmittance, hardness, and adhesion were measured, and the results were analyzed. It was confirmed that the contact angle and the anti-pollution characteristics were better when the coated substrate was annealed twice at 200 °C than when it was annealed only once.