A substrate processing method comprising: holding a substrate substantially horizontally by a rotatable substrate holding mechanism; supplying a rinsing liquid onto the top of the substrate held by the substrate holding mechanism at the substrate holding step; after the rinsing liquid supply step, spraying a gas onto the top of the substrate held by the substrate holding mechanism, by a gas knife mechanism, to form a gas spraying zone on the substrate top, and unidirectionally scanning the substrate top in its entirety by this gas spraying zone, without rotating the substrate; replenishing the rinsing liquid by supplying, in parallel to the gas knife spraying step, a rinsing liquid onto the substrate top at its area downstream in the gas-spraying-zone scanning direction rather than the gas spraying zone formed by the gas knife mechanism; and drying the substrate surface after the gas knife spraying step and the rinsing liquid replenishing step.