SURFACE SHAPE MEASUREMENT METHOD AND SURFACE SHAPE MEASUREMENT DEVICE

摘要

In this surface shape measuring method, white light (8A) having different wavelengths is separated into reference light (8C) and measurement light (8B). The measurement light (8B) is caused to be incident on a measurement surface (3). The reference light (8C) is caused to be incident on a first diffraction grating (20). The reference light (8C), which follows a first light path from the first diffraction grating (20) so as to be incident on a second diffraction grating (21), and thereafter follows the first light path from the second diffraction grating (21) so as to be incident on the first diffraction grating (20) and is emitted from the first diffraction grating (20), and the measurement light (8B) reflected by the measurement surface (3) are combined as interfering light (8D). The surface shape of the measurement surface (3) is thus measured.