A laser oscillation cooling device comprising: a light emitting section that is configured to emit laser excitation light; a laser excitation section that is configured to be excited by the laser excitation light to emit laser light and that locally generates heat in operation; a storage tank capable of storing an extremely low temperature liquid in a sub-cooled state; a pressurizing section that is configured to bring the extremely low temperature liquid into the sub-cooled state by pressurizing the inside of the storage tank; a jetting supply section that is configured to remove heat from the laser excitation section by applying a jet of the extremely low temperature liquid in the sub-cooled state onto the laser excitation section; a flow rate regulating section that is configured to change the amount of heat removed from the laser excitation section by regulating the flow rate of the extremely low temperature liquid supplied to the jetting supply section; a flow rate measurement section for measuring a flow rate of the extremely low temperature liquid; an output measurement section that is provided in the light emitting section to measure an output of the laser excitation light; and a control section that is configured to control the flow rate regulating section based on an output value measured by the output measurement section and to regulate the flow rate of the extremely low temperature liquid, wherein the control section includes an input storage section storing a table representing a relationship between the output value and a flow rate of the extremely low temperature liquid required under a situation of the output value, and configured to obtain a target flow rate value from the table based on the output value measured by the output measurement section, a calculation section configured to determine whether or not a difference between a flow rate value of the extremely low temperature liquid measured by the flow rate measurement section and the target flow rate value is equal to or less than a target value determined in advance, and an instruction section configured to instruct the flow rate regulating section to regulate the flow rate of the extremely low temperature liquid when the difference between the measured flow rate value and the target flow rate value is not equal to or less than the target value. a light emitting section that is configured to emit laser excitation light; a laser excitation section that is configured to be excited by the laser excitation light to emit laser light and that locally generates heat in operation; a storage tank capable of storing an extremely low temperature liquid in a sub-cooled state; a pressurizing section that is configured to bring the extremely low temperature liquid into the sub-cooled state by pressurizing the inside of the storage tank; a jetting supply section that is configured to remove heat from the laser excitation section by applying a jet of the extremely low temperature liquid in the sub-cooled state onto the laser excitation section; a flow rate regulating section that is configured to change the amount of heat removed from the laser excitation section by regulating the flow rate of the extremely low temperature liquid supplied to the jetting supply section; a flow rate measurement section for measuring a flow rate of the extremely low temperature liquid; an output measurement section that is provided in the light emitting section to measure an output of the laser excitation light; and a control section that is configured to control the flow rate regulating section based on an output value measured by the output measurement section and to regulate the flow rate of the extremely low temperature liquid, wherein the control section includes an input storage section storing a table representing a relationship between the output value and a flow rate of the extremely low temperature liquid required under a situation of the output value, and configured to obtain a target flow rate value from the table based on the output value measured by the output measurement section, a calculation section configured to determine whether or not a difference between a flow rate value of the extremely low temperature liquid measured by the flow rate measurement section and the target flow rate value is equal to or less than a target value determined in advance, and an instruction section configured to instruct the flow rate regulating section to regulate the flow rate of the extremely low temperature liquid when the difference between the measured flow rate value and the target flow rate value is not equal to or less than the target value. an input storage section storing a table representing a relationship between the output value and a flow rate of the extremely low temperature liquid required under a situation of the output value, and configured to obtain a target flow rate value from the table based on the output value measured by the output measurement section, a calculation section configured to determine whether or not a difference between a flow rate value of the extremely low temperature liquid measured by the flow rate measurement section and the target flow rate value is equal to or less than a target value determined in advance, and an instruction section configured to instruct the flow rate regulating section to regulate the flow rate of the extremely low temperature liquid when the difference between the measured flow rate value and the target flow rate value is not equal to or less than the target value.