An image reading apparatus includes an image reading unit having image reading means for reading an image; a first original carriage for carrying an original and for reading an original image in contact with an image reading unit which is moving; a second original carriage for carrying an original and for reading an original image in contact with an image reading unit which is in a stationary state; a stay provided between the first original carriage and the second original carriage; urging means for urging the image reading unit toward the first original carriage or toward the second original carriage; a guide portion, provided outside an image reading region, for guiding the image reading unit away from the stay when the image reading unit moves between the first original carriage and the second original carriage; and a member to be guided slidable relative to the guide when the image reading unit moves between the first original carriage and the second original carriage, the member to be guided in being disposed at a balanced position in a moving direction of the image reading unit and is substantially in line contact with the guide portion. |