Provided is a flexible device with fewer defects caused by a crack or a flexible device having high productivity. A semiconductor device including: a display portion over a flexible substrate, including a transistor and a display element; a semiconductor layer surrounding the display portion; and an insulating layer over the transistor and the semiconductor layer. When seen in a direction perpendicular to a surface of the flexible substrate, an end portion of the substrate is substantially aligned with an end portion of the semiconductor layer, and an end portion of the insulating layer is positioned over the semiconductor layer.