A document feeder includes an apparatus body to which a document feed unit is attached, a sheet feed tray that moves up and down toward the document feed unit, an open/close cover attached openably and closably to the apparatus body and opens the document transport path and the document feed unit when opened, and a unit pressing arm attached to the open/close cover. When the open/close cover is closed, the unit pressing arm presses the document feed unit toward the sheet feed tray.