Provided is an image reading device includes a document transport device that sequentially transports a plurality of documents one by one, and the image reading device sequentially reads the plurality of documents transported by the document transport device one by one. The image reading device includes a document discharge tray, a document discharge detector that detects whether or not a document of the plurality of documents is discharged to the document discharge tray, a notifier that notifies that the document of the plurality of documents discharged to the document discharge tray is forgotten to take, and a controller that activates the notifier if it is determined that a last document among the plurality of documents is read and the document discharge detector detects that the document of the plurality of documents is discharged to the document discharge tray.