A substrate processing apparatus according to the present disclosure includes: a nozzle that ejects a processing liquid to a wafer; a force-feeding unit that force-feeds the processing liquid to the nozzle side; a liquid feeding pipeline that includes first and second valves and guides the processing liquid from the force-feeding unit to the nozzle; and a controller. The controller is configured to perform opening the first valve in a state where the second valve is closed and a pressure between the first and second valves is higher than a pressure between the force-feeding unit and the first valve, controlling the force-feeding unit to increase the pressure between the first and second valves that has been decreased by the opening of the first valve, and opening the second valve after the pressure between the first and second valves is decreased by the opening of the first valve.