A pretreatment process, carried out prior to a developing process, spouts pure water, namely, a diffusion-assisting liquid for assisting the spread of a developer over the surface of a wafer, through a cleaning liquid spouting nozzle onto a central part of the wafer to form a puddle of pure water. The developer is spouted onto the central part of the wafer for prewetting while the wafer is rotated at a high rotating speed to spread the developer over the surface of the wafer. The developer dissolves the resist film partly and produces a solution. The rotation of the wafer is reversed, for example, within 7 s in which the solution is being produced to reduce the water-repellency of the wafer by spreading the solution over the entire surface of the wafer. Then, the developer is spouted onto the rotating wafer to spread the developer on the surface of the wafer.