Substrate processing apparatus and substrate processing method

A substrate processing apparatus, comprising:

• a substrate rotator configured to hold and rotate a substrate;
• a processing liquid supply configured to supply a processing liquid to the substrate held by the substrate rotator;
• an anode and a cathode configured to apply a voltage to the processing liquid supplied from the processing liquid supply;
• and
• a controller configured to control the substrate rotator, the processing liquid supply, and the anode and the cathode,
• wherein the controller allows, by contacting the anode and the cathode with the processing liquid independently, the processing liquid in contact with the anode and the processing liquid in contact with the cathode to be supplied to the substrate while being spaced apart from each other when the substrate is rotated,
• wherein at least one of the anode or the cathode is in direct or indirect contact with the processing liquid retained by a liquid retaining member, and
• the controller controls both the processing liquid in contact with the anode and the processing liquid in contact with the cathode to be supplied to a peripheral portion of the substrate.