The present invention relates to a substrate processing apparatus useful for plating a substrate or processing a substrate by dipping a substrate in a processing liquid. A substrate processing apparatus of the present invention includes: a loading/unloading area for carrying in and out a substrate; a cleaning area for cleaning the substrate; and a plating area for plating the substrate. The loading/unloading area is provided with a substrate transfer robot having a plurality of hands of dry-use design, a loading port mounted with a cassette for housing substrates, and a reversing machine of dry-use design for reversing the substrate from face up to face down.