| 摘要 |
A reference surface (11a) is moved, relative to an optical system (14), to a plurality of placement positions, and a wavefront of reflected light from a reference surface (11a) is measured at the respective placement positions by a detection unit (9). Based on information on the wavefront measured at the respective placement positions and information on the optical system, a plurality of pieces of shape data of the reference surface (11a) are calculated. Thereafter, a wavefront of reflected light from a measurement target surface (12a) is measured, and temporary shape data of the measurement target surface (12a) is calculated. Error data is calculated based on a relationship between the plurality of placement positions and the plurality of pieces of shape data at the respective positions, and the error data is removed from the temporary shape data thereby determining shape data of the measurement target surface (12a). |
