An object of this invention is to limit a correction amount for correcting the exposure error of a photographed image so as to prevent an excessively corrected image sensing result, and obtain a desired image sensing result by changing the correction width of the correction amount in accordance with the setting state and operation state of an image sensing apparatus and the object brightness in image sensing. To achieve this object, an exposure error value is calculated from the exposure level of an image signal and an exposure level obtained by photometry. The correction amount of the exposure error value is calculated on the basis of at least one of the setting state of the image sensing apparatus, the operation state of the image sensing apparatus, and the object brightness state in image sensing. The exposure error of the sensed image is corrected using the correction amount.