Image reading apparatus

An image reading apparatus equipped with an image reading apparatus unit (B) provided a platen and reading means that reads an original, a document feeder (A) provided conveyance paths (P), (P), and (P) leading from a sheet supply tray to a discharge tray via the platen on a top surface of the image reading apparatus unit (B), a hinge device that openably connects the document feeder (A) to a top surface of the image reading apparatus unit (B), wherein an image reading unit is equipped in the document feeder (A), and the image reading unit is integrally connected to a support member fastened to the hinge device. This configuration prevents mispositioning or misalignment of a reading line of the image reading unit caused by repeated opening and closing of the document feeder (A).