An apparatus for forming a window of a display panel includes a mold configured to hold a plate in a concave portion, wherein the concave portion has a predetermined shape, and a transfer part configured to sequentially transfer the mold to a heating part, a forming part, and a cooling part. The heating part includes first and second heating modules respectively positioned on top and bottom portions of the mold and configured to apply heat to the top and bottom portions of the mold. The forming part is positioned above the mold and configured to jet a high-temperature gas onto the heated plate. The cooling part includes first and second cooling modules respectively positioned on the top and bottom portions of the mold and configured to cool the top and bottom portions of the heated plate. The mold is tilted at a predetermined angle relative to a horizontal plane.