An a-Si film is patterned into a linear shape (ribbon shape) or island shape on a glass substrate. The upper surface of the a-Si film or the lower surface of the glass substrate is irradiated and scanned with an energy beam output continuously along the time axis from a CW laser in a direction indicated by an arrow, thereby crystallizing the a-Si film. This implements a TFT in which the transistor characteristics of the TFT are made uniform at high level, and the mobility is high particularly in a peripheral circuit region to enable high-speed driving in applications to a system-on glass and the like.