A coating film is formed by the steps of supplying a mixture of a solvent for dissolving a coating liquid and a volatilization suppressing substance for suppressing the volatilization of the solvent onto the surface of the target substrate W, expanding the mixture onto the entire surface of the target substrate W, and supplying a coating liquid onto substantially the central portion of the target substrate W that has received the mixture while rotating the target substrate W thereby expanding the coating liquid outward in the radial direction of the target substrate W thereby forming a coating film.