A feeding device includes: a sheet housing unit; a sheet conveying unit having an endless belt member, which faces a topmost sheet of sheets stacked in the sheet housing unit, and a suction unit disposed inside the belt member; a sheet lifting unit that lifts the topmost sheet to a position where the topmost sheet is attracted on a surface of the belt member by a negative pressure generated by the suction unit; and an external device sheet conveying unit that conveys a sheet fed from another feeding device connected to the feeding device to a gap between the topmost sheet in the sheet housing unit and the belt member. In feeding the sheet fed from the other feeding device to the subsequent step, the sheet lifting unit is stopped while the suction unit, the belt member, and the external device sheet conveying unit are operated.