A refrigerant control system includes: a storage part which stores a first refrigerant; a first sub-pipe which is connected to an outlet side pipe of a first circulation flow path; a second sub-pipe which is connected to an inlet side pipe of the first circulation flow path; a third sub-pipe which is connected to the inlet side pipe and is formed so that heat of the third sub-pipe lower than heat of the outlet side pipe is able to be transferred to the first refrigerant in the storage part a first opening and closing valve which is provided in the first sub-pipe; a second opening and closing valve which is provided in the second sub-pipe; a third opening and closing valve which is provided in the third pipe; and an opening and closing control unit which performs opening and closing control of the first opening and closing valve, the second opening and closing valve, and the third opening and closing valve on the basis of a set temperature of a second refrigerant.