A waste toner collecting apparatus separates waste toner remaining on an outer circumferential surface of a photosensitive medium when a visible image is transferred thereon and stores the separated waste toner. An electrophotographic image forming device includes the waste toner collecting apparatus. The waste toner collecting apparatus includes a cleaning blade that separates the waste toner from a photosensitive medium by scratching the outer circumferential surface of the photosensitive medium. A waste toner container stores the waste toner. The waste toner separated from the photosensitive medium is transported to the waste toner container through a waste toner passage. An agitating plate reciprocates inside the waste toner passage to prevent accumulation of the waste toner.