US Patent 9721814 Substrate processing apparatus

In a substrate processing apparatus, an election head from a position above a substrate held by a substrate holding part to an inspection position above a standby pod disposed outside a cup part. At the inspection position, a processing liquid ejected from the ejection head toward the standby pod is irradiated with planar light emitted from a light emitting part. An imaging part acquires an inspection image including bright dots appearing on the processing liquid, and a determination part determines the quality of the ejection operation of the ejection head on the basis of the inspection image. Accordingly, it is possible to eliminate the influence of reflected light from the substrate and droplets, mist, or the like of the processing liquid having collided with the substrate and to accurately determine the quality of the ejection operation of the ejection head.