An image reading apparatus, comprising: a flat bed reader on which a document is placed; a light emitting diode configured to illuminate capturing light onto the document placed on the flat bed reader; a carriage configured to receive a reflected light of the capturing light reflected by the document, the carriage being configured to move in a sub-scanning direction; light receiving elements linearly arranged so as to read an image from the document by moving the carriage along the sub-scanning direction while receiving the reflected light of the capturing light from the carriage; a clamp circuit configured to perform a clamping process with respect to each line of an image signal output from the light receiving elements; and an A/D converter configured to A/D convert the clamping-processed image signal by the clamp circuit to generate image data, characterized by an image correction unit configured to: detect a document area where the reflected light is abnormal by comparing first image data (Da) with second image data (Db); and replace the first image data (Da) corresponding to an abnormal document area with third image data (Dc), the first image data (Da) being generated by movement of the carriage in a sub-scanning direction of a first direction, the second image data (Db) being generated by movement of the carriage in the sub-scanning direction of a second direction at a reduced luminescence level of the capturing light illuminated on the document compared with a luminescence level in the movement of the carriage in the first direction, the third image data (Dc) being cut image data (Dc) where at least brightness is adjusted, wherein the cut image data (Dc) is a cut part from the second image data (Db) which is cut at a position corresponding to the abnormal document area. a flat bed reader on which a document is placed; a light emitting diode configured to illuminate capturing light onto the document placed on the flat bed reader; a carriage configured to receive a reflected light of the capturing light reflected by the document, the carriage being configured to move in a sub-scanning direction; light receiving elements linearly arranged so as to read an image from the document by moving the carriage along the sub-scanning direction while receiving the reflected light of the capturing light from the carriage; a clamp circuit configured to perform a clamping process with respect to each line of an image signal output from the light receiving elements; and an A/D converter configured to A/D convert the clamping-processed image signal by the clamp circuit to generate image data, characterized by an image correction unit configured to: detect a document area where the reflected light is abnormal by comparing first image data (Da) with second image data (Db); and replace the first image data (Da) corresponding to an abnormal document area with third image data (Dc), the first image data (Da) being generated by movement of the carriage in a sub-scanning direction of a first direction, the second image data (Db) being generated by movement of the carriage in the sub-scanning direction of a second direction at a reduced luminescence level of the capturing light illuminated on the document compared with a luminescence level in the movement of the carriage in the first direction, the third image data (Dc) being cut image data (Dc) where at least brightness is adjusted, wherein the cut image data (Dc) is a cut part from the second image data (Db) which is cut at a position corresponding to the abnormal document area.