It is an object of the present invention to provide a method of separating a thin film transistor, and circuit or a semiconductor device including the thin film transistor from a substrate by a method different from that disclosed in the patent document 1 and transposing the thin film transistor, and the circuit or the semiconductor device to a substrate having flexibility. According to the present invention, a large opening or a plurality of openings is formed at an insulating film, a conductive film connected to a thin film transistor is formed at the opening, and a peeling layer is removed, then, a layer having the thin film transistor is transposed to a substrate provided with a conductive film or the like. A thin film transistor according to the present invention has a semiconductor film which is crystallized by laser irradiation and prevents a peeling layer from exposing at laser irradiation not to be irradiated with laser light.