摘要 |
A method for manufacturing a diffraction grating having a plurality of grating grooves that extends in parallel in a direction includes a first cutting processing step of moving, in the direction, a work and a cutting tool having a first blade and a second blade relatively to each other, and of forming a first surface of the grating groove in the work through cutting processing using the first blade of the cutting tool, and a second cutting step of moving, in the direction, the work and the cutting tool relatively to each other after the first cutting processing step, so that the first blade does not contact the first surface formed by the first cutting processing step, and of forming a second surface of the grating groove in the work through cutting processing using the second blade of the cutting tool. |