A crystallization apparatus includes a light modulation element, and an image forming optical system that forms a light intensity distribution set based on light transmitted through the light modulation element on an irradiation surface. The crystallization apparatus irradiates a non-single crystal semiconductor film with light having the light intensity distribution to generate a crystallized semiconductor film. A curvature radius of at least one isointensity line of a light intensity substantially varies along the isointensity line in the light intensity distribution on the irradiation surface, and a curvature radius of at least a part of the isointensity line has a minimum value of 0.3 μm or below.