A substrate processing apparatus includes a substrate holding unit which holds and rotates a substrate in a horizontal orientation, a substrate heating unit which has a heating surface which faces the substrate, held by the substrate holding unit, from below and overlaps with an outermost periphery of the substrate in top view, and heats the substrate in a state of contacting a lower surface of the substrate, a transferring unit which transfers the substrate between the substrate holding unit and the substrate heating unit, and a processing fluid supplying unit which supplies a processing fluid toward the substrate held by the substrate holding unit.