The objective is to obtain a particle radiation therapy device that can use an easy-to-manufacture ridge filter without having to secure more space from scanning electric magnet to object for irradiation, wherein the particle radiation therapy device has irradiation portion (18) comprising scanning electric magnet (5) for scanning particle radiation performed within vacuum duct (4) and irradiating upon the object for irradiation, and beam bring-out windows (7a, 7b) for bringing out particle radiation from the vacuum duct to the atmosphere, and the irradiation portion is constituted in a manner that the vacuum duct is divisibly disposed upon flange face (47) closer to the side of object for irradiation than the scanning electric magnet, and when vacuum duct for scan-type irradiation method (6) provided closer to the side of object for irradiation than the flange face is removed for not overlapping upon beam line (1) of the particle radiation, ridge filter for broad beam irradiation method (42) is able to be disposed in a space provided with the vacuum duct for scan-type irradiation method before remove upon the beam line of the particle radiation.本發明之目的係在於獲得一種不需要較多的從掃描電磁鐵至照射對象之空間,且可使用製造容易之脊波導濾波器的粒子束治療裝置。本發明之粒子束治療裝置係具有:掃描電磁鐵(5),用以掃描行進於真空導管(4)內之粒子束並照射於照射對象;以及照射部(18),具備從真空導管取出粒子束至大氣中的射束取出窗(7a、7b),照射部係真空導管以能夠在比掃描電磁鐵還靠近照射對象側之凸緣面(47)進行分割的方式設置,且在使設置於比凸緣面還靠近照射對象側的掃描式照射法用真空導管(6),以不重疊於粒子束之射束線(1)上的方式移動時,以能夠將寬束照射法用之脊波導濾波器(42)設置在粒子束之射束線上並於移動前設置有掃描式照射法用真空導管之空間的方式所構成。1‧‧‧射束線4、15‧‧‧真空導管5、5a、5b‧‧‧掃描電磁鐵6‧‧‧掃描式照射法用真空導管7a‧‧‧射束取出窗11‧‧‧照射基準點12‧‧‧偏向電磁鐵18‧‧‧照射部41‧‧‧散射體42‧‧‧脊波導濾波器43‧‧‧範圍移動器47‧‧‧凸緣面48‧‧‧閘閥60‧‧‧真空導管移動機構61‧‧‧脊波導濾波器移動機構
