A toner cartridge is configured by integrally arranging a fresh toner storing chamber and a residual toner collection chamber. Fresh toner is filled in the fresh toner storing chamber through a fresh toner filling opening. Residual toner is conveyed in the residual toner collection chamber through a residual toner conveying opening. Two residual toner discharging openings are created in the residual toner collection chamber through which the residual toner is discharged.