A photoelectric conversion apparatus comprises a photoelectric conversion element including an avalanche photodiode for photoelectrically converting an optical image; an image generating unit configured to generate a first image based on a signal that has been acquired by the photoelectric conversion element; an acquisition unit configured to acquire first characteristic information of the photoelectric conversion element; a first correction processing unit configured to perform first correction processing for correcting linearity of the first image using the first characteristic information; and a second correction processing unit configured to perform second correction processing for performing interpolation based on the first characteristic information and information of the first image.