A display device includes a coordinate input device including a transparent substrate having a first signal interconnect disposed in a region outside a detection region corresponding to a contact position, a first electrode terminal, a flexible interconnect substrate connected to the first electrode terminal, and a display panel for image display based on a video signal from an external system. The coordinate inputting device has a second signal interconnect disposed outside the first signal interconnect but near the peripheral edge of the transparent substrate, the second signal interconnect surrounding the area where the detection region is included and the first signal interconnect is formed, the second signal interconnect being opened at opposite ends thereof and being connected to respective electrode terminals for inspection at the open ends, and the second signal interconnect is disposed along the peripheral edge portion of three sides of the transparent substrate.