Storage device and storage method

A storage device, comprising:

• a storage tank that stores a processing liquid that contains an aqueous solution of phosphoric acid and an additive;
• a heater that heats the processing liquid that is stored in the storage tank;
• a circulation route that discharges the processing liquid that is stored in the storage tank from the storage tank and returns the processing liquid to the storage tank, the heater being provided on the circulation route;
• a liquid sending route that branches from the circulation route and sends the processing liquid to a processing tank where a process for a substrate is executed;
• a controller that is configured to control the heater to execute a concentration maintaining process where a temperature of the processing liquid is adjusted to control an amount of evaporation of water for the processing liquid in the storage tank to be a same as an amount of absorption of moisture for the processing liquid in the storage tank, and
• a processing liquid supply that supplies the processing liquid to the storage tank, wherein
• the controller is further configured to control the processing liquid supply to execute a storing process where the processing liquid is stored in the storage tank and control the heater to execute a concentrating process where the processing liquid that is stored in the storage tank is concentrated by heating thereof, before the concentration maintaining process,
• in the concentration maintaining process, the heater is controlled to heat the processing liquid in such a manner that an amount of the processing liquid in the storage tank after the concentrating process is maintained, so that the amount of evaporation of water for the processing liquid in the storage tank is a same as the amount of absorption of moisture for the processing liquid in the storage tank,
• the controller is further configured to
• execute the concentration maintaining process within at least a part of a period of time after the concentrating process and before a liquid sending process is started where the processing liquid that is stored in the storage tank is sent to the processing tank,
• execute the concentrating process in such a manner that a heating temperature of the processing liquid is preliminarily determined as a temperature where the amount of evaporation of water for the processing liquid exceeds the amount of absorption of moisture for the processing liquid, and
• execute the concentration maintaining process in such a manner that the processing liquid is heated at a temperature that is higher than an ordinary temperature and is lower than the heating temperature.