A waste toner collecting apparatus using a disposable OPC drum utilizes an inside space of the disposable OPC drum as a waste toner container to collect waste toner. The waste toner collecting apparatus comprises a waste toner removing unit contacting one side of the OPC drum to remove the waste toner from the OPC drum, first transport unit transporting the waste toner, which is removed by the waste toner removing unit from the OPC drum, in one direction, a second transport unit transporting waste toner, which is transported by the first transport unit, to one side of a storage unit, and a screw member moving the waste toner, which is moved to one side of the storage unit, to the other side of the storage unit to store the waste toner within the storage unit from the one side to the other side without leaving an unused hollow space. A user can conveniently remove the waste toner by replacing only the OPC drum instead of individually replacing the OPC drum and the waste toner container.