Abstract: In a substrate treatment method for supplying a coating solution to a substrate with projections and depressions on a front surface thereof to form a coating film on the front surface of the substrate, the coating solution is supplied to the rotating substrate to form a coating film on the front surface of the substrate, and the substrate having the coating film formed thereon is heated to adjust an etching condition of the coating film. Next, the etching solution is supplied to the rotating substrate to etch the coating film, and thereafter the coating solution is supplied to the substrate to form a flat coating film on the front surface of the substrate. Thereafter, the substrate is heated to cure the coating film. This flattens the coating film with uniformity and high accuracy without undergoing a high-load process such as chemical mechanical polishing.