PROBLEM TO BE SOLVED: To improve accuracy and yield of characteristics of a ridge filter.SOLUTION: A ridge filter 100 mounted on a particle beam therapy system includes: a repeating structure body 101 provided with a plurality of extending parts 101c extending along an incident direction P of a particle beam 204； and a bottom plate 102 mounted on a side of a lower surface 101b opposite to the incident side of the particle beam 204 of the repeating structure body 101. Further, the repeating structure body 101 and the bottom plate 102 are integrally formed by a shaping method, and the repeating structure body 101 and the bottom plate 102 are each composed of a resin laminate.SELECTED DRAWING: Figure 5【課題】リッジフィルタにおける特性の精度および歩留りを高める。【解決手段】粒子線治療装置に設けられるリッジフィルタ１００であり、粒子線２０４の入射方向Ｐに沿って延びる複数の延在部１０１ｃを備えた繰り返し構造体１０１と、繰り返し構造体１０１の粒子線２０４の入射側と反対側の下面１０１ｂ側に設けられた底板１０２と、を有している。さらに、繰り返し構造体１０１と底板１０２とが、造形方法によって一体に形成され、かつ繰り返し構造体１０１と底板１０２とが、それぞれ樹脂の積層体からなる。【選択図】図５
