A coating film forming apparatus that holds a substrate upon a spin chuck and forms a coating film by supplying a chemical liquid upon a top surface of said substrate comprises: an outer cup provided detachably to surround the spin chuck; an inner cup provided detachably to surround a region underneath the substrate held upon the chuck; a cleaning nozzle configured to supply a cleaning liquid for cleaning a peripheral edge part of the substrate, such that the cleaning liquid is supplied to a peripheral part of a bottom surface of the substrate; a cutout part for nozzle mounting, the cutout part being provided to the inner cup to engage with the cleaning nozzle; and a cleaning liquid supply tube connected to the cleaning nozzle, the cleaning nozzle being detachable to the cutout part in a state in which the cleaning liquid supply tube is connected.