A plate loading device according to an embodiment includes an upper frame and a lower frame that face each other and are spaced apart from each other in a first direction, multiple side members disposed between the upper frame and the lower frame that extend in the first direction, and multiple supporting parts, wherein the side members include a first side member and a second side member facing each other, the first side member and the second side member each have multiple holes, and multiple supporting parts pass through respective ones of the holes.