A tablet cassette of tablet medicine packing apparatus is disclosed. The tablet cassette includes a tablet outlet opened such that tablets contained inside thereof to be discharged, a drum opening and closing the tablet outlet selectively, a lever controlling movement of the drum when the cartridge is separated from the cartridge installation unit, wherein the lever includes a drum contacting unit to be pressed elastically in the direction of contacting with the drum, while the drum contacting unit is separated from the drum when the cartridge is mounted on the cartridge installation unit.
