A temperature control apparatus for adjusting the temperature of circulating liquid, supplying the circulating liquid to a load that is external, and controlling the temperature of the load to a predetermined temperature, the temperature control apparatus comprising: a circulation circuit, wherein the circulation circuit includes a main tank storing circulating liquid and including a heater configured to heat the circulating liquid, a discharge flow passage configured to connect the main tank to a circulating liquid discharge port configured to deliver the circulating liquid to the load, a circulation pump configured to deliver the circulating liquid from the main tank to the discharge flow passage, and a return flow passage configured to connect a circulating liquid return port configured to receive the circulating liquid returned from the load to the main tank; a cooling circuit, wherein the cooling circuit includes a sub-tank storing the circulating liquid, a heat exchanger configured to cool the circulating liquid in the sub-tank by heat exchange with heat dissipating water, a first cooling flow passage configured to connect the sub-tank to the heat exchanger and guide the circulating liquid in the sub-tank to the heat exchanger, a cooling pump configured to deliver the circulating liquid in the sub-tank to the first cooling flow passage, and a second cooling flow passage configured to connect the heat exchanger to the sub-tank and guide the circulating liquid cooled by the heat exchanger to the sub-tank; and a processor configured to control the flow rate of the circulating liquid flowing through the cooling circuit, wherein the sub-tank is connected to the main tank such that when an amount of the circulating liquid in the main tank exceeds a predetermined amount, excessive circulating liquid is led from the main tank to the sub-tank, wherein the second cooling flow passage of the cooling circuit includes a connecting flow passage that branches from the second cooling flow passage and that is connected to the circulation circuit, wherein the circulation circuit includes a temperature sensor (61, 30) configured to measure the temperature of the circulating liquid flowing in the circulation circuit, and wherein the processor controls an output of the cooling pump based on the temperature of the circulating liquid measured by the temperature sensor so as to control the flow rate of the circulating liquid supplied from the inside of the cooling circuit to the inside of the circulation circuit through the connecting flow passage. a circulation circuit, wherein the circulation circuit includes a main tank storing circulating liquid and including a heater configured to heat the circulating liquid, a discharge flow passage configured to connect the main tank to a circulating liquid discharge port configured to deliver the circulating liquid to the load, a circulation pump configured to deliver the circulating liquid from the main tank to the discharge flow passage, and a return flow passage configured to connect a circulating liquid return port configured to receive the circulating liquid returned from the load to the main tank; a cooling circuit, wherein the cooling circuit includes a sub-tank storing the circulating liquid, a heat exchanger configured to cool the circulating liquid in the sub-tank by heat exchange with heat dissipating water, a first cooling flow passage configured to connect the sub-tank to the heat exchanger and guide the circulating liquid in the sub-tank to the heat exchanger, a cooling pump configured to deliver the circulating liquid in the sub-tank to the first cooling flow passage, and a second cooling flow passage configured to connect the heat exchanger to the sub-tank and guide the circulating liquid cooled by the heat exchanger to the sub-tank; and a processor configured to control the flow rate of the circulating liquid flowing through the cooling circuit, wherein the sub-tank is connected to the main tank such that when an amount of the circulating liquid in the main tank exceeds a predetermined amount, excessive circulating liquid is led from the main tank to the sub-tank, wherein the second cooling flow passage of the cooling circuit includes a connecting flow passage that branches from the second cooling flow passage and that is connected to the circulation circuit, wherein the circulation circuit includes a temperature sensor (61, 30) configured to measure the temperature of the circulating liquid flowing in the circulation circuit, and wherein the processor controls an output of the cooling pump based on the temperature of the circulating liquid measured by the temperature sensor so as to control the flow rate of the circulating liquid supplied from the inside of the cooling circuit to the inside of the circulation circuit through the connecting flow passage.