A substrate treating apparatus is provided for eliminating wasteful consumption of a treating solution in a treating mode in which the treating solution is delivered in a strip form to a substrate from a treating solution delivery nozzle sweeping over the substrate. In a first aspect of the invention, collecting vessels are arranged around a developing cup surrounding a wafer supported by a wafer holder. The collecting vessels collect part of a developer delivered from a discharge opening of a developer delivery nozzle outwardly of a surface of the wafer. In a second aspect of the invention, collecting vessels are arranged below a developer delivery nozzle, with collecting openings of the collecting vessels opposed to a discharge opening or openings of the delivery nozzle. The collecting vessels are moved longitudinally of the discharge openings according to a position of the developer delivery nozzle relative to the wafer.