PURPOSE: To provide a polycrystalline silicon TFT where the ON current is large and the OFF current is small.

CONSTITUTION: Shading films 2a and 2b which intercept the lamp light of an RTA device or the laser light of a laser anneal device, are made on a transparent insulating substrate 1. A cap film 3 is made thereon, and a polycrystalline silicon film 4 to serve as an active layer is made thereon, and source and drain regions 5a and 5b are made in the polycrystalline silicon film 4. In the polycrystalline silicon film 4, both ends of the channel region 7 between the source and drain regions 5a and 5b are replaced with amorphous silicon films 6a and 6b. A gate insulating film 8 is made on the polycrystalline silicon film 4 and the transparent insulating substrate 1. A gate electrode 9 is made on the channel region 7 through the gate insulating film 8. An interlayer insulating film 10 is made all over the surface of the device, and each contact hole 11a and 11b is made on each film 8 and 10, and each source and drain electrode 12a and 12b are made.