An image reading device capable of performing double-sided reading job which reads both sides of a document alternately at a single read position by turning over the document, comprising: a document setting tray on which the document is set; an image reader configured to read the document in the read position; a document discharge tray onto which the document after reading is discharged; a main transport path from the document setting tray via the read position to the document discharge tray; the reversing transport path branching from the main transport path on a downstream side of the read position and joining the main transport path on an upstream side of the read position of the main transport path; a document transport controller for controlling to transport the document along the main transport path, and controlling to transport the document whose one side has been read in the read position along the reversing transport path so as to turn over the document and to transport the turned-over document to the read position when performing the double-sided reading job; and an operation portion configured to accept a setting instruction concerning the double-sided reading job, wherein the document transport controller controls to discharge the document in one of two sheet discharging modes including a first sheet discharging mode in which the document is turned over again after both sides of the document have been read in the read position and then is discharged onto the document discharge tray, and a second sheet discharging mode in which the document is discharged onto the document discharge tray without being turned over again, the operation portion accepts an instruction to select one of the first sheet discharging mode and the second sheet discharging mode to discharge the document, and when the second sheet discharging mode is selected, the operation portion accepts the number of sheets of the document to be discharged in the second sheet discharging mode among the sheets of the document set on the document setting tray, and the document transport controller controls to discharge the sheets of the document corresponding to the number of sheets accepted by the operation portion in the second sheet discharging mode. a document setting tray on which the document is set; an image reader configured to read the document in the read position; a document discharge tray onto which the document after reading is discharged; a main transport path from the document setting tray via the read position to the document discharge tray; the reversing transport path branching from the main transport path on a downstream side of the read position and joining the main transport path on an upstream side of the read position of the main transport path; a document transport controller for controlling to transport the document along the main transport path, and controlling to transport the document whose one side has been read in the read position along the reversing transport path so as to turn over the document and to transport the turned-over document to the read position when performing the double-sided reading job; and an operation portion configured to accept a setting instruction concerning the double-sided reading job, wherein the document transport controller controls to discharge the document in one of two sheet discharging modes including a first sheet discharging mode in which the document is turned over again after both sides of the document have been read in the read position and then is discharged onto the document discharge tray, and a second sheet discharging mode in which the document is discharged onto the document discharge tray without being turned over again, the operation portion accepts an instruction to select one of the first sheet discharging mode and the second sheet discharging mode to discharge the document, and when the second sheet discharging mode is selected, the operation portion accepts the number of sheets of the document to be discharged in the second sheet discharging mode among the sheets of the document set on the document setting tray, and the document transport controller controls to discharge the sheets of the document corresponding to the number of sheets accepted by the operation portion in the second sheet discharging mode.