A load-lock system includes a load-lock chamber arranged between a storage port which stores a substrate and a process chamber which processes the substrate in a process space maintained at a pressure lower than that in the storage port, and a dehumidifying unit which forms a dehumidified environment in the load-lock chamber. A system preferably includes another chamber between said storage port and said load-lock chamber, wherein said dehumidifying unit dehumidifies said another chamber.