A method for manufacturing a display device includes preparing a display device including a display panel including a first alignment mark and a first circuit board including a second alignment mark and on one end of the display panel, disposing the display device on a stage including a base mark, setting the base mark as a reference mark in consideration of a relative position relation between the first alignment mark and the base mark by sensing the first alignment mark and the base mark, and determining a bending state of the display device by sensing the base mark and the second alignment mark and identifying a position relation between the base mark and the second alignment mark.