Patent Number: 
Section: claims

1. A charged particle beam therapy apparatus comprising:an accelerator configured to accelerate a charged particle and to emit a charged particle beam;an irradiation unit configured to irradiate an irradiation subject with the charged particle beam; anda ridge filter that is provided in the irradiation unit and generates a spread out Bragg peak of the charged particle beam,wherein the ridge filter includes a damping member configured for reducing energy of the charged particle beam, in an intersecting direction which intersects an irradiating direction of the charged particle beam,wherein the damping member includes a cross-sectional area changing along the irradiating direction and includes a side surface in a case of being seen in the intersecting direction, being bonded to a side surface of another damping member, andwherein a pass-through portion passing through the ridge filter in the irradiating direction is formed at a position different from a position of the damping member in a case of being seen in the irradiating direction. 2. The charged particle beam therapy apparatus according to claim 1,wherein the intersecting direction has a first direction and a second direction which intersects the first direction, andwherein the damping member is one of a plurality of damping members which individually have a pyramid shape, are arranged along the first direction, and are arranged along the second direction. 3. A ridge filter for a charged particle beam therapy apparatus generating a spread out Bragg peak of a charged particle beam, the ridge filter comprising:a damping member configured for reducing energy of an incident charged particle beam in an intersecting direction which intersects an irradiating direction of the charged particle beam,wherein the damping member includes a cross-sectional area changing along the irradiating direction and includes a side surface in a case of being seen in the intersecting direction, being bonded to a side surface of another damping member, andwherein a pass-through portion passing through the ridge filter in the irradiating direction is formed at a position different from a position of the damping member in a case of being seen in the irradiating direction.