An image sensing apparatus comprises an image sensing unit including an image sensor having a plurality of image sensing pixels and a plurality of focus detection pixels discretely arranged between the plurality of image sensing pixels, a shift detection unit that detects a shift amount between images obtained by a plurality of image sensing operations, a combining unit that combines signals of the focus detection pixels contained in the images obtained by the plurality of image sensing operations on the basis of the shift amount detected by the shift detection unit, and a focus adjustment unit that adjusts a focus of the imaging lens by using signals of the focus detection pixels before combined by the combining unit, and signals of the focus detection pixels that are combined by the combining unit.