To reduce the construction cost at the time of attaching a regenerative heat exchanger to a refrigerator.

When building a cold accumulative cooling system 1 by attaching a regenerative heat exchanger 9, an expansion valve 8 for a regenerative heat exchanger, and a bypass duct 10 for cold accumulation to a refrigerator where a compressor 2, a condenser 3, an expansion valve 4 or an evaporator, and an evaporator 5 are connected in order by refrigerant pipes, the bypass pipe 10 for cold accumulation is so attached as to branch from a first refrigerant pipe 6, and pass the expansion valve 8 for a regenerative heat exchanger, and the regenerative heat exchanger 9 in order, and join the first refrigerant pipe 6 again downstream of this divergence.