In order to fabricate a high performance thin film semiconductor device using a low temperature process in which it is possible to use low price glass substrates, a thin film semiconductor device has been fabricated by forming a silicon film at less than 450 DEG C., and, after crystallization, keeping the maximum processing temperature at or below 350 DEG C. In applying the present invention to the fabrication of an active matrix liquid crystal display, it is possible to both easily and reliably fabricate a large, high-quality liquid crystal display. Additionally, in applying the present invention to the fabrication of other electronic circuits as well, it is possible to both easily and reliably fabricate high-quality electronic circuits.