A bill sterilizer includes a counting machine having a bill input part, a bill sensing part and a bill discharge part a body having an opening and a receiving space a tray provided on the floor of the receiving space an ion generator located on the wall surface of the receiving space a door to block the opening of the receiving space and a door lock located on the front face below the opening of the body to fix the door. The bill sterilizer equipped with the counting machine supplies cluster negative ions to the sterilizer body so that the cluster negative ions are evenly transferred to the surfaces of the bills after the whole counting machine for counting the number of the bills is located inside the bill sterilizer.
