Abstract: A thin film semiconductor which comprises a substrate, a single crystalline silicone thin film layer and an intermediate layer disposed between the substrate and the single-crystalline silicon thin film layer. Coefficient of the thermal expansion of the intermediate layer is between those of the substrate and the single-crystalline silicon. The intermediate layer absorbs thermal stress and relaxes strain remaining in the silicon layer, which strain is generated due to difference of thermal expansion coefficient between the substrate and the silicon layer. Due to the arrangement of the intermediate layer, it becomes possible to use various material as the substrate without generating micro-cracks and produce a semiconductor device using a large sized substrate.