1. A method of inspecting defects on an object comprising: irradiating predetermined particles with a laser beam to measure first scattered light intensities; irradiating plural types of defects with the laser beam to measure second scattered light intensities; determining types of some defects selected out of the plural types of defects using the first scattered light intensities; setting, based on the determination, a discrimination line indicating a boundary value of the second scattered light intensities, the boundary value being in dependence on the types; and discriminating, using the discrimination line, defects on the object.