A particle beam irradiation system comprising: a synchrotron accelerating an ion beam and having the accelerated ion beam extracted therefrom; an irradiation device for executing irradiation with the ion beam extracted from the synchrotron; and a controller for causing operation control data about component devices making up the synchrotron to be formed by at least one initial acceleration control data item, a plural extraction control data items for ion beam extraction at a plural energy stages, a plural energy change control data items connecting the plural extraction control data items, and a plural deceleration control data items corresponding to the plural extraction control data items, the controller further combining the control data items (701, 702, 705, 706) to provide beam extraction control at a plural energy stages, wherein the controller holds, as the plural extraction control data items, extraction condition setting data items for setting extraction conditions and extraction condition cancellation data items for canceling the extraction conditions, wherein the extraction condition setting data items and the extraction condition cancellation data items constituting the plural extraction control data items are used to control a quadrupole magnet and a sextupole magnet positioned in the synchrotron, wherein the plural extraction control data items are arranged in such a manner that the initial value of the magnetic field intensity of the quadrupole magnet and the sextupole magnet of the extraction condition setting data items is the same as the final value of the magnetic field intensity of the quadrupole magnet and the sextupole magnet of the extraction condition cancellation data items respectively and that the final value of the magnetic field intensity of the quadrupole magnet and the sextupole magnet of the extraction condition setting data items is the same as the initial value of the magnetic field intensity of the quadrupole magnet and the sextupole magnet of the extraction condition cancellation data items respectively, wherein the extraction condition setting data items change the value of the magnetic field intensity of the quadrupole magnet and the sextupole magnet, and wherein the extraction condition cancellation data items change the value of the magnetic field intensity of the quadrupole magnet and the sextupole magnet. a synchrotron accelerating an ion beam and having the accelerated ion beam extracted therefrom; an irradiation device for executing irradiation with the ion beam extracted from the synchrotron; and a controller for causing operation control data about component devices making up the synchrotron to be formed by at least one initial acceleration control data item, a plural extraction control data items for ion beam extraction at a plural energy stages, a plural energy change control data items connecting the plural extraction control data items, and a plural deceleration control data items corresponding to the plural extraction control data items, the controller further combining the control data items (701, 702, 705, 706) to provide beam extraction control at a plural energy stages, wherein the controller holds, as the plural extraction control data items, extraction condition setting data items for setting extraction conditions and extraction condition cancellation data items for canceling the extraction conditions, wherein the extraction condition setting data items and the extraction condition cancellation data items constituting the plural extraction control data items are used to control a quadrupole magnet and a sextupole magnet positioned in the synchrotron, wherein the plural extraction control data items are arranged in such a manner that the initial value of the magnetic field intensity of the quadrupole magnet and the sextupole magnet of the extraction condition setting data items is the same as the final value of the magnetic field intensity of the quadrupole magnet and the sextupole magnet of the extraction condition cancellation data items respectively and that the final value of the magnetic field intensity of the quadrupole magnet and the sextupole magnet of the extraction condition setting data items is the same as the initial value of the magnetic field intensity of the quadrupole magnet and the sextupole magnet of the extraction condition cancellation data items respectively, wherein the extraction condition setting data items change the value of the magnetic field intensity of the quadrupole magnet and the sextupole magnet, and wherein the extraction condition cancellation data items change the value of the magnetic field intensity of the quadrupole magnet and the sextupole magnet.