To provide a substrate processing device and a substrate processing method, wherein a sponge-like substrate cleaning brush can be effectively cleaned, substrate cleaning can be carried out with high quality, and the running cost of the substrate processing device can be reduced.

A first brush 31 and a second brush 32 of both sponge-like structure are pressed against the periphery of a substrate from sideways to clean the peripheral region of the substrate. In a period that no substrate is processed, a behavior that the first brush 31 and the second brush 32 are pressed against each other to be compressed, another behavior that the first brush 31 and the second brush 32 are parted from each other to be expanded are alternately repeated, and a cleaning liquid is supplied toward the first and second brush 31 and 32 from a cleaning liquid supply nozzle 17. By this setup, the first brush 31 and the second brush 32 are alternately compressed and expanded, and contaminants are squeezed out together with the cleaning liquid and discharged out.