PURPOSE: To rapidly detect the flaw of an optical information recording medium with high accuracy, by irradiating an org. membrane with white light through an optical filter capable of cutting a wavelength equal to ore less than the max. absorption wavelength of the org. membrane and detecting the partial variation of the transmitted light thereof.

CONSTITUTION: An optical filter 3 cutting a wavelength equal to or less than the max. absorption wavelength of an org. membrane is used in this flaw inspection method. At this time, since the quantity of detection light itself is reduced in a filter cutting the wavelength in a long wavelength region, detection capacity is lowered and effect of a certain degree is shown in a filter cutting the wavelength in a short wavelength region but detection capacity is gradually lowered. By inspecting the flaw of the org. membrane of an optical information recording medium 4 by the visual observation of transmitted light using an apparatus constituted of a light source 1, a diffusion plate 2, an optical filter 3 and a lens system 5, the flaw can be detected rapidly and easily with high accuracy as compared with conventional visual inspection with white light not passed through the optical filter.