A display device includes a protective layer comprising a first area, a second area, a third area, and a fourth area; a first island part comprising a buffer layer disposed on a substrate; and a semiconductor layer disposed on the buffer layer; a second island part comprising a first gate insulating layer disposed on the first area; and a first metal layer disposed on the first gate insulating layer; a third island part comprising a second gate insulating layer disposed on the second area; and a second metal layer disposed on the second gate insulating layer; and a fourth island part comprising an interlayer dielectric layer disposed on the third area and a third metal layer disposed on the interlayer dielectric layer, and disposed in the fourth area of the protective layer.