A packing mounting and removing device includes a packing mounting and removing rod, a rod support, a rod fixing nut, and a spiral line. The packing mounting and removing device includes a packing flange having a through hole, a gland bushing, a packing, and a lantern ring. A packing exchange method uses the same. By using the device it is not necessary to use any special equipment for removing the packing, and it is possible to mount and remove the packing without disassembling a driving section and a valve disc section. Therefore, it is possible to noticeably reduce time and cost required for the mounting and removing the packing.