An automatic sheet transporting apparatus comprising: a transporting unit comprising a discharge roller, the transporting unit configured to discharge a sheet; a discharge tray configured to support at least one sheet discharged from the transporting unit in a stack; a discharge guide positioned on an upstream side of the discharge tray in a sheet discharging direction, the discharge guide configured to guide a subsequent sheet transported by the transporting unit to a position between the discharge tray and a bottom surface of a previously discharged sheet in the stack; and at least one rotating member positioned in the discharge tray, the at least one rotating member configured to rotate when the discharge guide guides the subsequent sheet to the position between the discharge tray and the bottom surface of the previously discharged sheet in the stack; characterised in that: the discharge tray comprises a pair of supporting panels configured to support both widthwise end portions of discharged sheets; the at least one rotating member comprises at least one pair of rotating members and a portion of the peripheral surface of each rotating member of the at least one pair of rotating members projects through at least one opening formed through a corresponding surface of one supporting panel of the pair of supporting panels; and each supporting panel of the pair of supporting panels is movable in a direction intersecting the sheet discharging direction. a transporting unit comprising a discharge roller, the transporting unit configured to discharge a sheet; a discharge tray configured to support at least one sheet discharged from the transporting unit in a stack; a discharge guide positioned on an upstream side of the discharge tray in a sheet discharging direction, the discharge guide configured to guide a subsequent sheet transported by the transporting unit to a position between the discharge tray and a bottom surface of a previously discharged sheet in the stack; and at least one rotating member positioned in the discharge tray, the at least one rotating member configured to rotate when the discharge guide guides the subsequent sheet to the position between the discharge tray and the bottom surface of the previously discharged sheet in the stack; characterised in that: the discharge tray comprises a pair of supporting panels configured to support both widthwise end portions of discharged sheets; the at least one rotating member comprises at least one pair of rotating members and a portion of the peripheral surface of each rotating member of the at least one pair of rotating members projects through at least one opening formed through a corresponding surface of one supporting panel of the pair of supporting panels; and each supporting panel of the pair of supporting panels is movable in a direction intersecting the sheet discharging direction. the discharge tray comprises a pair of supporting panels configured to support both widthwise end portions of discharged sheets; the at least one rotating member comprises at least one pair of rotating members and a portion of the peripheral surface of each rotating member of the at least one pair of rotating members projects through at least one opening formed through a corresponding surface of one supporting panel of the pair of supporting panels; and each supporting panel of the pair of supporting panels is movable in a direction intersecting the sheet discharging direction.