A first reading guide includes a first guide member, which can turn around a first shaft and is so positioned as to face a first side of a document. The second reading guide includes a second guide member, which can turn around a second shaft and is so positioned as to face a second side of a document. The distance between a first reading position and a reference position is equal to that between a second reading position and the reference position. The first shaft is positioned on the side of the reference position where the first reading position is set. The second shaft is positioned on the side of the reference position where the second reading position is set.