Substrate processing apparatus, substrate processing method, fluid supplying method and storage medium

A substrate processing apparatus comprising:

• a processing chamber configured to process a substrate by a supercritical fluid or a subcritical fluid;
• a fluid supplying unit configured to supply a fluid to the processing chamber;
• a first fluid supplying path and a second fluid supplying path each configured to be connected to the fluid supplying unit and the processing chamber;
• a first filter provided in the first fluid supplying path and configured to remove foreign matter in a gas state fluid;
• a second filter provided in the second fluid supplying path and configured to remove foreign matter in a liquid state fluid, a supercritical state fluid or a subcritical state fluid;
• a fluid path switching unit configured to switch over the first fluid supplying path and the second fluid supplying path in which the fluid supplied from the fluid supplying unit passes between the first fluid supplying path and the second fluid supplying path;
• and
• a control unit configured to output a control signal to the fluid path switching unit such that the fluid is supplied to the processing chamber through the first fluid supplying path during a period where the raw fluid supplied from the fluid supplying unit passes in the gas state and the fluid is supplied to the processing chamber through the second fluid supplying path during a period where the fluid obtained from the raw fluid passes in the liquid state, the supercritical state or the subcritical state.