an electrophotographic copying machine developer vessel includes a vessel proper having a closed top , a barrel and a tapered inclined portion continuous to the barrel . the developer vessel also includes a receiving plate removably attachable to the vessel proper , the receiving plate having a substantially flat supporting surface , substantially straight two side edges for attachment to the developing device and an opening communicating with the vessel proper . an opening tab composed of a film which covers the opening of the receiving plate is peelably bonded to the flat supporting surface thereof . a shutter is provided which includes a plate having , on both the sides thereof , engagement portions to be engaged with both the side edges of the receiving plate . the shutter may engage the receiving plate of the developer vessel such that when the developer vessel is removed from a copying machine , the presence of the shutter thereunder prevents scattering of developer in the environment .