An apparatus includes: a tank storing a processing liquid; a circulation line; a branch line; a processing part for supplying the processing liquid to a substrate at the branch line; a discharge part for reducing a storage amount of the processing liquid; a supply part for supplying a new processing liquid to the tank; and a controller including: a first determination part for determining whether the storage amount is less than a lower limit value; a first replenishment controller for replenishing the processing liquid to the tank when the storage amount is less than the lower limit value; a calculation part for calculating a replenishment amount of the processing liquid; and a second replenishment controller for reducing the storage amount and replenishing the processing liquid to the tank when a calculation value of the replenishment amount is less than a set value.