A sheet discharging device includes: sheet discharging rollers that receive each of sheets conveyed thereto and discharge the sheets one by one; a shift tray on which the sheets discharged by the sheet discharging rollers are to be stacked; an air blower; and a CPU. The air blower forms an air layer between the shift tray and a sheet when the sheet is discharged onto the shift tray by the sheet discharging rollers, or between a sheet and the sheet that is already placed on the shift tray when the sheet is discharged. The CPU controls an air velocity of air to be delivered by the air blower based on sheet information, thereby causing the air layer to extend to the entire surface of the sheet.