An image reading apparatus which performs shading correction using black reference data, characterized in that: the image reading apparatus comprises: light sources of each RGB color; an image sensor that transfers charge accumulated in a photoelectric conversion device to a shift register using shift pulses and outputs the charge transferred to the shift register as analog data and a reading control section that outputs a shift pulse which is the start timing of charge accumulation corresponding to each RGB color and controls the process of lighting of the light source of a predetermined color for a predetermined period after a predetermined period having elapsed since the output of each shift pulse.