A crystalline semiconductor film in which the locations and sizes of crystal grains have been controlled, is prepared, and a TFT capable of high speed operation is realized by employing the crystalline semiconductor film as the channel forming region of the TFT. An organic resin film (2 in FIG. 1) having a predetermined shape is provided on a substrate (1), whereupon an inorganic insulating film (3) and an amorphous semiconductor film are formed. Subsequently, the amorphous semiconductor film is crystallized by laser annealing. The material and thickness of the organic resin film (2) in the predetermined shape or those of the inorganic insulating film (3) are properly regulated, whereby the cooling rate of the semiconductor film is lowered to form a first region (4a) in which crystal grain diameters are large.