Substrate processing apparatus

A substrate processing apparatus comprising:

• a plurality of processing units stacked and arranged with each other, and each configured to hold a substrate in a chamber and to process the substrate by a processing liquid;
• and
• a plurality of gas supply units provided for the plurality of processing units, respectively, to supply a gas into the plurality of processing units, respectively,
• wherein each of the plurality of gas supply units includes:
• an intake unit including a filter and configured to take in an outside air and purify the outside air into a clean air by the filter;
• and
• an air supply unit arranged above the chamber so as to be opened at the chamber side, connected to the intake unit laterally so as to communicate with the intake unit, and configured to supply the clean air purified by the intake unit into the plurality of processing units,
• wherein the intake unit is arranged on a lateral side of the chamber, and is arranged on same side face of each of chambers of the plurality of processing units.