A load port provided adjacent to a wafer transport chamber for taking in and out a wafer W between the wafer transport chamber and a FOUP, includes a plate-shaped part that constitutes a part of a wall of the wafer transport chamber, and has an opening for opening the wafer transport chamber; a door part for opening and closing the opening; a mounting table that is configured to mount a wafer storage container so as to oppose a lid part for opening and closing an internal space to the door part, and to move to and from the plate-shaped part; and an elastic part that is provided on the mounting table side of the plate-shaped part along the peripheral edge of the opening, wherein the elastic part elastically contacts the periphery of the lid part in the wafer storage container by moving the mounting table toward the plate-shaped part.