A substrate processing apparatus includes a substrate holder that holds a substrate in a horizontal direction; a rotation driver that rotates the substrate holder; a first processing liquid nozzle that supplies a first processing liquid to a peripheral portion of the substrate; a first gas supply source that supplies a first gas at a first temperature to the peripheral portion of the substrate; and a second gas supply source that supplies a second gas at a second temperature to an inner side of the substrate in a radial direction. The first gas supply source includes a heater that heats the first gas into the first temperature, and a first gas ejection port that supplies the first gas heated by the heater through a conduit, and the second gas supply source includes a second gas ejection port that supplies the second gas through a gas supply pipe.