A developing apparatus including a substrate holder that holds a substrate horizontally; means for atomizing a surface treatment liquid used to improve wettability of the substrate with a developer; a first spray nozzle that sprays the atomized surface treatment liquid onto the substrate; and a developer supply nozzle that supplies a developer onto the substrate to which the substrate treatment liquid has been sprayed. The surface tension of the atomized surface treatment liquid with respect to the substrate is lower than the surface tension of the surface treatment liquid with respect to the substrate. The atomization suppresses the fact that the surface treatment liquid gathers on a certain portion of the surface of the substrate. The surface treatment liquid can be easily supplied onto the entire surface of the substrate, and improve wettability of the substrate with the developer.