| 摘要 |
PROBLEM TO BE SOLVED: To obtain an apparatus for focusing of simple structure which can be adjusted relatively easily and can precisely focus even on a substrate surface with steps. SOLUTION: An apparatus for focusing including a focus sensor 5 irradiating a substrate 4 with sensor light, a focus detector 6 receiving the reflected light of the sensor light irradiated by the focus sensor 5, a focus calculation unit 7 detecting the height of thickness direction of the substrate 4 with the quantity of the reflected light of the sensor light received by the focus detector 6 and calculating the focal position is provided with one focus sensor 5, one focus detector 6, and even a means for scanning irradiation position scanning the irradiation position of the focus sensor 5 in the irradiated area in a grid pattern. |
