A substrate processing apparatus includes: a nozzle unit configured to discharge a processing liquid to a substrate; a pipe connected to the nozzle unit and a processing liquid supply unit supplying the processing liquid; a charge amount control unit disposed at the pipe, including a filter unit charged with positive charges or negative charges, and including at least one of a control valve, controlling a flow rate of the processing liquid passing through an inside of the filter unit, and a power supply unit, applying a voltage to the filter unit, to control a charge amount of the processing liquid; and a control unit connected to the charge amount control unit.