Patent ID: 7061603

Claim:
A method for inspecting an exposure device, comprising: a step of guiding light emitted from an illumination optical system to a photomask where a pattern is formed of an optical member including a light transmission pattern as a diffraction grating pattern, in which a first light transmission part and a second light transmission part having a lower transmittance than the first light transmission part are repeated in a predetermined direction, a plurality of ratios are given between lengths of the first and second light transmission parts in a repetition direction, phases of lights which pass through the first and second light transmission parts adjacent to each other differ from each other, and a periphery of the light transmission pattern is shielded by an opaque area, such that a plurality of ratios are given between the first light transmission part and the second light transmission part; a step of irradiating diffraction light, which has passed through the photomask, onto a projection optical system, thereby to transfer the pattern to a wafer and to form a pattern reflecting an intensity distribution of the diffraction light; and a step of measuring a change of transmittance depending on a light path of the projection optical system, based on a pattern image of the diffraction light transferred to the wafer.