Patent Number: 
Section: claims

1. A particle beam therapy system comprisingan irradiation unit having a scanning electromagnet for irradiating an irradiation object by scanning a particle beam which travels in a vacuum duct and a beam outlet window from which a particle beam comes out from the vacuum duct to the atmosphere,wherein the irradiation unit has the configuration such that a vacuum duct is provided which can be divided by a flange surface at an irradiation object side of the scanning electromagnet,in a case where a vacuum duct for a scanning irradiation method is provided at an irradiation object side of the flange surface, a ridge filter for a scanning irradiation method is provided at the irradiation object side of the vacuum duct for a scanning irradiation method,in a case where the vacuum duct for a scanning irradiation method is moved so as not to overlap with a beam line of the particle beam, the ridge filter for a scanning irradiation method is removed and a ridge filter for a broad beam irradiation method can be provided in space which is on a beam line of a particle beam and where the vacuum duct for a scanning irradiation method was provided before it was moved. 2. A particle beam therapy system according to claim 1, wherein the irradiation unit comprises a ridge filter transfer mechanism by which a ridge filter is moved to a beam line direction of the particle beam,in a case where the scanning irradiation method vacuum duct is moved so as not to overlap a beam line of the particle beam,in place of the ridge filter for a scanning irradiation method which is provided at the ridge filter transfer mechanism, the ridge filter for a broad beam irradiation method is provided at the ridge filter transfer mechanism, the ridge filter for a broad beam irradiation method is moved to close to a direction of the flange surface and is provided. 3. A particle beam therapy system according to claim 1, wherein a gate valve is provided at a position which is upper stream than the flange surface of the vacuum duct. 4. A particle beam therapy system according to claim 1, wherein the beam outlet window is provided on the flange surface in a case where the vacuum duct for a scanning irradiation method is moved so as not to overlap a beam line of the particle beam. 5. A particle beam therapy system according to claim 1, further comprises a plurality of the vacuum ducts for a scanning irradiation method whose length are different, a holding mechanism which holds the plurality of the vacuum ducts for a scanning irradiation method at a position which does not overlap the beam line and a vacuum duct transfer mechanism by which one of the plurality of the vacuum ducts for a scanning irradiation method can be moved from the holding mechanism to the beam line. 6. A particle beam therapy system according to claim 1, wherein the irradiation unit is mounted on a rotating gantry.