A measuring apparatus includes an optical system configured to project light onto a sample and to receive light via the sample, an imaging device configured to take an image of a light source via the optical system, and a processor configured to obtain an optical characteristic of the sample based on an output of the imaging device. The processor is configured to determine a coefficient of a Wiener filter based on one of the image and a Fourier transform thereof and corresponding one of the light source (an aperture in an aperture unit) and a Fourier transform thereof, and obtain the optical characteristic based on the Wiener filter of which the coefficient has been determined, a Fourier transform of the image, and a Fourier transform of the light source.