An image reading apparatus includes: a supply tray; a discharge tray, which is positioned below the supply tray to support the sheet; a conveyance guide, which conveys the sheet from the supply tray to the discharge tray; a reading sensor, which reads an image on the sheet conveyed on the conveyance guide; a discharge unit, which includes a discharge port to discharge the sheet conveyed by the conveyance guide to the discharge tray and is configured to move from a third position to a fourth position, the fourth position being higher than the third position; a first drive source, which generates a drive force; and a second drive source, which generates a drive force, wherein the movable plate is moved by the drive force from the first drive source, and the discharge unit is moved by the drive force from the second drive source.