摘要 |
PROBLEM TO BE SOLVED: To provide a substrate processing device and a substrate processing method, capable of accurately determining the position of an end part of a main surface of a substrate.SOLUTION: A processing liquid film is formed on a main surface of a substrate excluding a peripheral part P having a predetermined width on the main surface of the substrate inside the outermost peripheral part of the substrate. The peripheral part P and at least a part of the film on the main surface of the substrate are irradiated with light, and receive reflection light from the substrate. Light-receiving data corresponding to the light-receiving amount of the reflection light is acquired, and the position of an end part E of the main surface of the substrate is determined based on change of light-receiving data in a first direction from a reference position SP in the peripheral part P on the main surface of the substrate toward the outermost peripheral part of the substrate. |