Substrate treatment device and substrate treatment method

A substrate treatment method, which is performed by a substrate treatment apparatus,

• the substrate treatment apparatus comprising:
• a treatment vessel in which an etching treatment liquid containing an organic alkali component is retained and a substrate is immersed in the etching treatment liquid to be thereby treated with the etching treatment liquid;
• and
• a detector that detects a concentration of the etching treatment liquid in the treatment vessel to acquire a detection concentration,
• the substrate treatment method comprising:
• an acquiring step of acquiring an exhaustion degree of the etching treatment liquid;
• a computing step of computing the concentration of the etching treatment liquid with reference to the exhaustion degree of the etching treatment liquid and exhaustion degree information;
• and
• a controlling step of supplying the organic alkali component into the treatment vessel so that the detection concentration acquired by the detector is made equal to the concentration of the etching treatment liquid computed by the computing step;
• wherein the exhaustion degree information indicates a relationship between the concentration of the etching treatment liquid and the exhaustion degree of the etching treatment liquid.