A coating and developing system prevents wetting its component units with water when the coating and developing system forms a resist film on a substrate and processes the substrate processed by immersion exposure by a developing process. A substrate having a surface coated with a resist film and processed by immersion exposure is placed on a substrate support device and a liquid detector detects at least the liquid formed a liquid film for immersion exposure and remaining on the surface of the substrate. A decision is made as to whether or not the substrate needs to be dried on the basis of the result of detection made by the liquid detector. If it is decided that the substrate needs to be dried, the substrate is dried by a drying means. Thus wetting the interior of the coating and developing system with water can be prevented. Since only substrates that need to be dried are subjected to a drying process, the coating and developing system is able to operate at a high throughput.