Only a region where TFTs constituting a high-performance circuit will be disposed in a precursor semiconductor film PCS on an insulating substrate GLS with an insulating layer UCL serving as an undercoat is irradiated with a first energy beam LSR so as to be poly-crystallized while growing crystal grains laterally. Further a second rapid thermal treatment is performed all over the panel so as to reduce defects in the crystal grains in a region PSI poly-crystallized by the aforementioned energy beam. Thus, a high-quality polycrystalline semiconductor thin film serving as TFTs for a high-performance circuit and having a high on-current, a low threshold value, a low variation and a sharp leading edge characteristic is obtained. Concurrently, the precursor semiconductor layer in the other region is poly-crystallized by the second rapid thermal treatment so as to obtain a low-quality polycrystalline semiconductor thin film serving as pixel circuit TFTs and having a low on-current and properties of a low leak current and a high withstand voltage due to its high resistance. Accordingly, it is possible to form polycrystalline semiconductor TFTs high in driving performance and TFTs having properties of a low leak current and a high withstand voltage concurrently on one and the same insulating substrate.

The present invention provides an image display device free of display defects and with high reliability to prevent destruction of electron sources due to injection of electric charge.On the outermost periphery of a display region, there are provided a bottom electrode 11 serving as data line, a scan line bus 21 serving as scan line, and dummy potential fixing electrodes 11D1, 11D2, 21D1 and 21D2 not contributing to image display, and these are connected with electrodes 70 and 80 with low impedance and constant potential.