A manufacturing method of a highly reliable semiconductor with a waterproof property. The method includes the steps of: sequentially forming a peeling layer, an inorganic insulating layer, and an element formation layer including an organic compound layer, over a substrate; separating the peeling layer and the inorganic insulating layer from each other, or separating the substrate and the inorganic insulating layer from each other; removing a part of the inorganic insulating layer or a part of the inorganic insulating layer and the element formation layer, thereby isolating at least the inorganic insulating layer into a plurality of sections so that at least two layers among the organic compound layer, a flexible substrate, and an adhesive agent are stacked at outer edges of the isolated inorganic insulating layers; and cutting a region where at least two layers among the organic compound layer, the flexible substrate, and the adhesive agent are stacked.