Substrate processing system and state monitoring method

A method of monitoring a state of a member within a substrate processing apparatus in a substrate processing system including the substrate processing apparatus and a substrate transfer mechanism,

• wherein the substrate processing system is configured such that the substrate transfer mechanism includes a substrate holder and loads and unloads a substrate into and out of the substrate processing apparatus while holding the substrate on the substrate holder, and
• the substrate processing system further includes an imaging device provided in the substrate transfer mechanism and configured to image a monitoring target member inside the substrate processing apparatus, and
• wherein the method comprises:
• causing the imaging device to image multiple portions of the monitoring target member, including a central portion facing a center of the substrate during processing and a peripheral edge portion facing a peripheral edge side of the substrate during processing, by moving the substrate holder;
• and
• calculating, for each of the multiple portions of the monitoring target member, a physical amount indicating a state of the corresponding portion based on an imaging result in the causing the imaging device to image the multiple portions.