Substrate treating method

A substrate processing method comprising:

• a substrate holding step of holding a substrate substantially horizontally by a substrate holding mechanism, the substrate holding mechanism configured to be rotated by a substrate rotating unit for rotation of the substrate;
• a rinsing liquid supply step of supplying a rinsing liquid onto a top of the substrate held by the substrate holding mechanism at the substrate holding step;
• a gas knife step of spraying, after the rinsing liquid supply step, 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 of unidirectionally scanning the substrate top in its entirety by the gas spraying zone, with the substrate holding mechanism not rotated by the substrate rotating unit;
• a rinsing liquid replenishing step of supplying, in parallel to the gas knife step, a rinsing liquid onto the substrate top at its area downstream in the gas-spraying-zone scanning direction with respect to the gas spraying zone formed by the gas knife mechanism;
• and
• a drying step of drying the substrate top after the gas knife step and the rinsing liquid replenishing step.