This substrate processing method includes: a substrate rotating step of rotating a substrate around a predetermined vertical axis line at a first rotation speed; a liquid-tight step performed along with the substrate rotating step, and where a first opposed surface is opposed at a first distance to a rotated lower surface of the substrate, and at the same time, a processing liquid is discharged from a processing liquid dispense port of a lower surface nozzle opposed to the lower surface of the substrate to cause a space between the lower surface and the first opposed surface to be in a liquid-tight state by the processing liquid; and a liquid-tight state releasing step of releasing the liquid-tight state in the space between the lower surface and the first opposed surface by separating the lower surface and the first opposed surface after the liquid-tight step.