A pattern inspection apparatus in accordance with one aspect of the present invention includes a laser light source configured to emit a laser light, an integrator lens configured to input the laser light, and form a light source group by dividing the laser light inputted, a scattering plate, arranged at a front side of an incident surface of the integrator lens, configured to scatter the laser light which is to enter the integrator lens, and an inspection unit configured to inspect a defect of a pattern on an inspection target object where a plurality of figure patterns are formed, by using the laser light having passed through the integrator lens as an illumination light.