Arrangement detector for plate-shaped object and load port including same

An arrangement detector for plate-shaped objects and a lord port including the same are provided. The arrangement detector for plate-shaped objects includes a judgement window setting means, a shape determination means for determining a shape matching rate by superimposing the judgement window on the image captured by the imaging means, and an object judgement means for judging the plate-shaped objects do not exist in the judgement window overlaid on the image captured by the imaging means, in case that the shape matching rate determined by the shape determination means is equal to or less than a predetermined value. A first reference line is a continuous straight line in the judgement window, and a second reference line is a collection of discontinuous line segments linearly arranged in the judgement window.