A sheet discharging device includes a shift tray 202 on which a sheet P1 is stacked, a discharging roller 6 that discharges a sheet P2 onto the shift tray 202, a blowing device 230 that sends air to a lower surface of the sheet P2 discharged by the discharging roller 6, a blocking member 231 that blocks air sent to the lower surface of the sheet P2 from a blowing port 230-2 of the blowing device 230, and a control unit that controls the blocking amount of the blocking member 231. The blocking amount is determined based upon sheet information including sheet-type information, sheet-size information, and sheet-thickness information, for example.