An apparatus (100) for processing substrates includes: a substrate cleaning device (20), which cleans the substrates with treating liquid; a developing device (40); and a treating liquid recovery system (30), which is connected with the cleaning device and the developing device. The treating liquid recovery system can convey the treating liquid from the cleaning device to the developing device. Thus the treating liquid that has been used in the cleaning device can be reused in the developing device. Therefore the apparatus can economize on treating liquid and reduce costs.