A substrate processing apparatus removes foreign substances from a substrate at high removal efficiency. The substrate processing apparatus includes: a scrubber to perform surface processing of the substrate by bringing a scrubbing member into sliding contact with a first surface of the substrate, a hydrostatic support mechanism for supporting a second surface of the substrate via fluid pressure without contacting the substrate, the second surface being an opposite surface of the first surface, a cleaner to clean the processed substrate, and a dryer to dry the cleaned substrate. The scrubber brings the scrubbing member into sliding contact with the first surface while rotating the scrubbing member about a central axis of the scrubber.