A plasma generation device includes a plasma head configured to eject plasma gas that is plasmatized, a gas supply device configured to supply gas serving as the plasma gas to the plasma head, a pair of electrodes that is provided in the plasma head, the pair of electrodes being configured to perform discharging for a part of the gas supplied from the gas supply device to generate the plasma gas, a temperature sensor that is provided in the plasma head, the temperature sensor being configured to measure a temperature of the plasma head; and a control device, in which the control device executes a cooling process of cooling the plasma head by causing the gas supply device to continue supply of the gas until the temperature sensor measures a temperature equal to or less than a predetermined value after the discharging of the pair of electrodes is stopped.