An image sensing apparatus comprises an image sensing element having an image sensing unit configured to include an effective pixel area in which light is incident on arrayed pixels and a shading pixel area in which the arrayed pixels are shaded, analog-to-digital conversion units connected one-to-one to columns of the arrayed pixels, a feedback control unit configured to output, commonly on an input side of each of the analog-to-digital conversion units, an offset compensation signal for compensating for an amount of error between a reference value and an output signal of the shading pixel area output from at least one of the analog-to-digital conversion units, and offset compensation units arranged one-to-one on the input side of each of the analog-to-digital conversion units, and to compensate for offset by subtracting an output signal of the feedback control unit from an output signal of the effective pixel area.