A two-dimensional laser beam profiler has been developed that can measure the intensity distribution on a sample surface of a single-shot of an excimer-laser light beam from not only the macroscopic viewpoint, but also the microscopic viewpoint, which is important to excimer-laser triggered lateral large-grain growth of Si. A resolution as fine as 0.4 µm was obtained with a field of view of as large as 30 µm 30 µm. The effects of homogenizers, phase-shifters, and their combination on beam profiles were quantitatively investigated by using this apparatus. The relationship between the microscopic beam profile and the surface morphology of laterally grown grains was also examined.