Therapy planning device includes total data administrative unit, for storing target irradiation dosage distribution, it is formed in object, wide radiation parameters computing unit, with the device of scanning radiation parameters computing unit Collaboration computing and determining operating parameter, such as accelerator irradiates nozzle, in order to operate in wide radiation and a scanning irradiation, so that summation forms the distribution of target irradiation dosage with by two wide dose of radiation irradiation scanning irradiations.