A system for circulating hyperthermic pressurized gas in a peritoneal cavity, comprising: a gas circulation device that comprises a gas hose (13, 33, 35), which is connected to a peritoneal cavity of a subject, and a pump (12, 32) which is connected to the gas hose and circulates gas, and that circulates gas discharged from the peritoneal cavity back to the peritoneal cavity; and a temperature control device that controls a gas temperature of the gas circulation device such that gas in the peritoneal cavity has a set temperature, wherein the gas circulation device comprises: an intraperitoneal gas injecting unit through which gas is injected into the peritoneal cavity; and a circulation unit which discharges gas to outside from the peritoneal cavity, circulates the gas at the outside of the peritoneal cavity, and injects the gas back into the peritoneal cavity, wherein the intraperitoneal gas injecting unit comprises a drug-and-gas spray device that sprays a drug together with gas during gas injection into the peritoneal cavity of the subject, wherein the circulation unit comprises a first trocar which is cannulated into the peritoneal cavity and discharges gas, a circulation hose as a gas hose which is connected to the first trocar, and a circulation pump which is connected to the circulation hose and increases pressure of circulating gas, wherein the drug-and-gas spray device comprises: a drug syringe which supplies a drug; a drug-and-gas dispenser which is connected to the gas hose to be supplied with pressurized gas, is supplied with a drug from the drug syringe, and is cannulated into the peritoneal cavity to dispense a drug and gas into the peritoneal cavity of the subject; and a two-fluid nozzle (23; 23') which is disposed at an end of the drug-and-gas dispenser and through which the drug and gas are together sprayed into the peritoneal cavity, wherein the circulating gas of the circulation unit is supplied to both the drug-and-gas dispenser and a second trocar which is cannulated into the peritoneal cavity, and wherein the temperature control device comprises: a temperature sensor (42, 43, 44) which measures one or more of a gas temperature in the peritoneal cavity and a gas temperature of the gas circulation device at the outside of the peritoneal cavity; a heater that provides heat to at least a part of the gas hose of the gas circulation device; and a temperature controller that is connected to the heater and the temperature sensor (42, 43, 44). a gas circulation device that comprises a gas hose (13, 33, 35), which is connected to a peritoneal cavity of a subject, and a pump (12, 32) which is connected to the gas hose and circulates gas, and that circulates gas discharged from the peritoneal cavity back to the peritoneal cavity; and a temperature control device that controls a gas temperature of the gas circulation device such that gas in the peritoneal cavity has a set temperature, wherein the gas circulation device comprises: an intraperitoneal gas injecting unit through which gas is injected into the peritoneal cavity; and a circulation unit which discharges gas to outside from the peritoneal cavity, circulates the gas at the outside of the peritoneal cavity, and injects the gas back into the peritoneal cavity, wherein the intraperitoneal gas injecting unit comprises a drug-and-gas spray device that sprays a drug together with gas during gas injection into the peritoneal cavity of the subject, wherein the circulation unit comprises a first trocar which is cannulated into the peritoneal cavity and discharges gas, a circulation hose as a gas hose which is connected to the first trocar, and a circulation pump which is connected to the circulation hose and increases pressure of circulating gas, wherein the drug-and-gas spray device comprises: a drug syringe which supplies a drug; a drug-and-gas dispenser which is connected to the gas hose to be supplied with pressurized gas, is supplied with a drug from the drug syringe, and is cannulated into the peritoneal cavity to dispense a drug and gas into the peritoneal cavity of the subject; and a two-fluid nozzle (23; 23') which is disposed at an end of the drug-and-gas dispenser and through which the drug and gas are together sprayed into the peritoneal cavity, wherein the circulating gas of the circulation unit is supplied to both the drug-and-gas dispenser and a second trocar which is cannulated into the peritoneal cavity, and wherein the temperature control device comprises: a temperature sensor (42, 43, 44) which measures one or more of a gas temperature in the peritoneal cavity and a gas temperature of the gas circulation device at the outside of the peritoneal cavity; a heater that provides heat to at least a part of the gas hose of the gas circulation device; and a temperature controller that is connected to the heater and the temperature sensor (42, 43, 44).