Substrate processing method, substrate processing device and etching liquid

A substrate processing method, comprising:

• holding a substrate;
• and
• supplying an etching liquid to the substrate held in the holding of the substrate, the etching liquid containing an etching agent configured to etch a metal-based first material and a silicon-based second material exposed on the substrate and a protection agent configured to react with the silicon-based second material between the metal-based first material and the silicon-based second material to form a protection layer on a surface of the silicon-based second material, the etching agent being a liquid which contains fluorine atoms and an organic solvent and substantially does not contain water, and the protection layer protecting the silicon-based second material from etching with the etching agent, and
• separating the organic solvent from a used etching liquid serving as the etching liquid in the supplying of the etching liquid,
• wherein the separating of the organic solvent includes:
• discharging the used etching liquid to a first drain line configured to discharge a processing liquid;
• and
• vaporizing the organic solvent contained in the used etching liquid by heating the used etching liquid flowing through the first drain line.