IRRADIATION NOZZLE, PARTICLE BEAM THERAPY DEVICE, PARTICLE BEAM THERAPY SYSTEM, AND CONTROL METHOD FOR PARTICLE BEAM THERAPY SYSTEM

To implement downsizing of an apparatus and highly accurate beam irradiation. An irradiation nozzle 4 that irradiates a target object Pt with a radiotherapy beam includes: a nozzle base part 42 fixed on a beam axis 40 through which the radiotherapy beam passes; and a nozzle tip part that irradiates the target object with the radiotherapy beam that has passed through the nozzle base part, in which the nozzle tip part is fixed at a first position when the target object is irradiated with the radiotherapy beam and is fixed at a second position when the target object is imaged, and a curved movement path in which the nozzle tip part is movable between the first position and the second position is provided.