Patent ID: 7431038

Claim:
A wet processing device comprising: a substrate holding device for holding a substrate in a horizontal position; a processing liquid pouring unit for pouring a processing liquid onto a surface of a substrate held by the substrate holding device; a cleaning liquid pouring nozzle for pouring a cleaning liquid onto the surface of the substrate held by the substrate holding device and processed by a wet process that pours the processing liquid onto the surface of the substrate; a cleaning liquid discharging unit provided with a discharge opening extending along an entire circumference of the substrate to discharge a cleaning liquid on a peripheral part of a back surface of the substrate held by the substrate holding device; and a first suction means provided with a suction opening extending along the entire circumference of the substrate to suck the cleaning liquid discharged on the peripheral part of the back surface of the substrate by the cleaning liquid discharging unit to produce a flow of the cleaning liquid flowing outward or inward along the back surface of the substrate so as to suck the liquid flowing from the surface to the back surface of the substrate together with the flow of the cleaning liquid; and wherein an overflow ridge higher than the discharge opening and the suction opening is formed between the cleaning liquid discharge opening of the cleaning liquid discharging unit and the suction opening of the first suction means, and a liquid flow in a space between the overflow ridge and the back surface of the substrate serves as a seal.