A semiconductor device is fabricated by forming a first crystalline region by irradiating a laser beam to a first region of an amorphous semiconductor film by relatively moving the laser beam with respect to the first region of the amorphous semiconductor film. A second crystalline region is formed by irradiating the laser beam to a second region of the amorphous semiconductor film including a portion of the first crystalline region by relatively moving the laser beam with respect to the second region of the amorphous semiconductor film. The wavelength of the laser beam falls in a range of 370 nm through 650 nm. In general, crystalline performance of the first crystalline region, the second crystalline region, and a region of overlap between the first crystalline region and the second crystalline region are the same.