A method for manufacturing a display device is provided. A process of forming an inspection pattern, in which a protective film unit is partially removed in a thickness direction, in a pad area portion of the protective film unit, which corresponds to a pad area of a display unit, may be performed, and then, a process of delaminating the pad area portion of the protective film unit may be performed. A process of checking whether the inspection pattern exists may be performed to check whether the delamination has succeeded, and, at the same time, a process of measuring distances from an alignment mark to each of a long side and a short side of the display unit may be performed.