Disclosed herein is a method for inspecting a transparent film. The method comprises irradiating an inspection target with light using a polarizer, receiving light that is reflected by the inspection target and passes through an analyzer by a line scan camera, synthesizing an amplitude and a phase of wavelength of the light into an intensity of light, comparing the intensity of the light with predetermined intensities of light for inspection targets having different thicknesses; and detecting a defect of the inspection target based on the compared intensity with the predetermined intensities. It can be determined whether there is a transparent film, and the thickness of the transparent film can be measured in a large area. The inspection is carried out in real-time after the transparent film is formed, such that if a defect is generated, it can be fed back immediately to thereby reduce defects. In this case, the processing cost can be saved.