In a substrate processing apparatus, with an internal space of a chamber brought into a pressurized atmosphere, an etching process is performed by continuously supplying a first processing liquid onto an upper surface of a substrate while rotating the substrate. It is thereby possible to suppress vaporization of the first processing liquid on the substrate and further suppress a decrease in the temperature of the substrate due to the heat of vaporization as it goes from a center portion of the substrate toward a peripheral portion thereof as compared with under normal pressure. As a result, it is possible to improve the uniformity in the temperature of the upper surface of the substrate during the etching process using the first processing liquid and improve the uniformity of etching over the entire upper surface of the substrate.