A substrate processing apparatus which holds and rotates a substrate substantially horizontally; having a control unit which controls a rinsing liquid supply mechanism for supplying a rinsing liquid onto the substrate; a gas knife mechanism that sprays gas onto the substrate to form a gas spraying zone and scans the entire substrate without rotating the substrate; a rinsing liquid mechanism for supplying a rinsing liquid onto the substrate at its area downstream from the gas spraying zone; and a drying unit for drying the substrate by rotating the substrate.