To provide an image reading device in which images of holes can be prevented from being conspicuous even at the time of reading a bookbound original having punch holes or the like in the neighborhood of a binding part.

The upper faces of right and left original placing plates 1 and 1 in a prescribed range in the neighborhood of the adjacent side edge parts of the original placing plates are formed as bright parts 1b, and the other part is formed as a black part 1a. Thus, at the time of reading a book bound original having punch holes or the like in the neighborhood of the binding part, the bright parts 1b on the original placing plates are exposed from punch holes P so that the punch holes can be prevented from being formed as black circles in a read picture. The neighborhood of the binding part of the bookbound original is illuminated from the opposite side to the original page face so that the position of the binding part can be surely recognized, and picture missing or unnecessary picture formation or the like can be prevented at the time of dividing and outputting right and left pages.