A display device includes a display panel, a first film attached to the display panel, an adhesive member interposed between the display panel and the first film and extending in a first direction to attach the display panel to the first film, a first test electrode covered by the adhesive member; a second test electrode covered by the adhesive member and spaced apart from the first test electrode in a second direction perpendicular to the first direction, and test lines comprising a first test line electrically connected to the first test electrode and a second test line electrically connected to the second test electrode, where the adhesive member is disposed between the first test electrode and the second test electrode in the second direction.