 when the inside temperature drops below the predetermined temperature, stopping the depressurizer and actuating the pressurizer to increase the inside gas pressure to a pressure equal to or more than the atmospheric pressure.  0. A quick freezing apparatus comprising:  a freezing store including a door for bringing in or taking out an object-to-be-frozen;  a freezer capable of lowering a temperature inside the freezing store to a temperature equal to or less than approximately −00 degrees centigrade;  a pressure regulator capable of adjusting a gas pressure inside the freezing store; and  a ventilator for sending cold air at a wind velocity of 0 to 0 m/sec toward the object-to-be-frozen placed inside the freezing store,  wherein the pressure regulator comprises a pressurizer for increasing the inside gas pressure to a pressure equal to or more than atmospheric pressure by supplying a pressurized gas into the freezing store, and  wherein the pressurizer comprises a pressurizing pump, and a gas introduction path of the pressurizing pump is connected to a circulating path through which a gas inside the freezing store is circulated.  0. A quick freezing apparatus comprising:  a freezing store including a door for bringing in or taking out an object-to-be-frozen;  a freezer capable of lowering a temperature inside the freezing store to a temperature equal to or less than approximately −00 degrees centigrade;  a pressure regulator capable of adjusting a gas pressure inside the freezing store; and  a ventilator for sending cold air at a wind velocity of 0 to 0 m/sec toward the object-to-be-frozen placed inside the freezing store,  wherein the pressure regulator comprises a depressurizer for decreasing the inside gas pressure to a pressure equal to or less than atmospheric pressure by drawing the inside gas, and  wherein the depressurizer comprises a suction pump, and a discharge side of the suction pump is connected to a circulating path through which a sucked gas is circulated to the inside of the freezing store.  0. The quick freezing apparatus according to claim 0, wherein the pressurizer comprises a pressurizing pump