Chemical supply apparatus and chemical supply method

A chemical supply method that supplies a chemical to a substrate processing apparatus from a chemical processing apparatus having a first tank and a second tank, the chemical supply method comprising:

• supplying a chemical stored in the first tank to the substrate processing apparatus and recovering a chemical used in the substrate processing apparatus to the first tank;
• supplementing the first tank with a chemical in the second tank, as needed;
• and
• a chemical exchange step of supplying a new chemical to the first tank when the chemical stored in the first tank reaches its lifetime,
• wherein the chemical in the second tank is supplied to the substrate processing apparatus in the chemical exchange step.

A chemical supply method that supplies a chemical to a substrate processing apparatus from a chemical processing apparatus having a first tank and a second tank, the chemical supply method comprising:

• supplying a chemical stored in the first tank to the substrate processing apparatus, discarding a chemical used in an early stage of the substrate processing apparatus, and recovering only the chemical used thereafter to the first tank;
• supplementing the first tank with a chemical from the second tank as needed, such that a specific component of the chemical stored in the first tank is maintained below a predetermined concentration;
• and
• a chemical exchange step of supplying a new chemical to the first tank when the chemical stored in the first tank reaches its lifetime,
• wherein, in the chemical exchange step, the chemical in the second tank is supplied to the substrate processing apparatus and the chemical used in the substrate processing apparatus is not recovered but is drained.