Patent ID: 8072592

Claim:
A reticle defect inspection method comprising: irradiating one surface of a reticle with a first inspection light through an optical system of transmitted illumination, wherein the first inspection light is emitted from a light source; irradiating another surface of the reticle with a second inspection light through an optical system of reflected illumination; detecting, simultaneously and with a detecting optical system, a transmitted light obtained by the first inspection light being transmitted through the reticle and a reflected light obtained by the second inspection light being reflected by the reticle; obtaining a first pattern image of the reticle by the transmitted light using a first imaging device; obtaining a second pattern image of the reticle by the reflected light using a second imaging device; and correcting a focal point shift of the transmitted light resulting from a thickness of the reticle by moving the focus lens in a direction of an optical axis of the first inspection light, wherein the focus lens is provided in the optical system of transmitted illumination, and the focus lens is located on an optical path between the light source and the reticle.