Provided is an electrophotographic image forming apparatus including: a toner buffer unit arranged between a toner cartridge and a developing unit to receive toner from the toner cartridge and supply the toner to the developing unit; and a toner level detection unit. The toner buffer unit includes a first buffer unit connected to the toner cartridge. A first conveyance member including a rotation shaft and a conveyance wing provided in the rotation shaft and transporting the toner in a radial direction is provided in the first buffer unit. The toner buffer unit includes an elevation plate provided in the first buffer unit and elevated according to a toner level, and a sensor unit detecting a location of the elevation of the elevation plate. The elevation plate is located to be spaced apart from the conveyance wing in an axial direction of the rotation shaft.