Abstract Radiative cooling glass is a new type of energy saving glass products that can prevent incoming heat flux and UV light through the window and transport heat from inside to outside the building by transforming into transparency windows wavelength (TWW). TWW is the wavelength from 8 to 13 microns that is called mid-infrared region (MIR) This MIR region does not interact with the atmosphere and can penetrate to space directly. Therefore, the radiative cooling glass is not only able to save energy in buildings, but it also reduces urban heat island effect. Silicon dioxide (SiO2) film is one component in radiative cooling glass that is employed as an absorption layer to absorb the MIR wavelength and transfer to other layers. This study investigates surface morphology and optical properties of SiO2 film on glass substrate at various coating conditions. A mixture solution of tetraethyl orthosilicate (TEOS), DI water and ethanol were sprayed through the nozzle with different concentration and volume at ambient atmosphere. Optical microscope results show the higher concentration of TEOS gives the rougher surface of SiO2 film due to formation and accumulation of SiO2 particles. However, UV-Vis spectroscopy results show that concentration of TEOS and thickness of the SiO2 film do not influence on percent transmittance of the SiO2 films