An objective of the present invention is to obtain multi-leaf collimators and particle beam therapeutic apparatuses capable of forming an irradiation filed with high contrast, without receiving influence of half-shadow.A particle beam therapeutic apparatus of the present invention includes a leaf row (5c) having a plurality of leaf plates (5L) arranged in a thickness direction with one end surfaces (EL) thereof being aligned with one another, and a leaf plate driving mechanism (5D) driving respective leaf plate (5L) to render the one end surfaces (EL) approach or separate from a beam axis (XB), wherein the respective leaf plate (5L) includes a surface (PL) opposing to a leaf plate adjacent to that leaf plate in the thickness direction which is formed in a plane (PSa) containing a first axis (Asa) on the beam axis (XB), and the leaf plate driving mechanism (5D) drives the leaf plates (5L) along a circle orbit (OL) having a second axis (Asb) on the beam axis (XB) separating away from the first axis (Asa) by a predetermined distance and perpendicular to the beam axis (XB) and the first axis (Asa) as the center.本發明的目的係獲得一種不受半影的影響,而可形成對比度較高的照射場之多片型射線調準器及粒子線治療裝置。本發明之多片型射線調準器係具備有:片列(5c),將複數個片板(5L)的一端面加以排列整齊並朝厚度方向排列;以及片板驅動機構(5D),對於片板(5L)之各者,使一端面(EL)朝射束軸(XB)接近或離開方向驅動;並且各個片板(5L)之該片板的與鄰接於厚度方向的片板的相對向面(PL),係形成在包含射束軸(XB)上的第一軸(ASa)的平面(PSa);而片板驅動機構(5D)係以垂直於射束軸(XB)上的射束軸(XB)及第一軸(Asa),且沿著從第一軸(ASa)以距離預定間隔的第二軸(Asb)為中心的圓形軌道(OL)來驅動片板(5L)。1‧‧‧搖擺電磁鐵1a‧‧‧x方向(上游)掃掠電磁鐵1b‧‧‧y方向(下游)掃掠電磁鐵2‧‧‧脊形過濾器3‧‧‧射程移位器4‧‧‧區塊射線調準器5‧‧‧多片型射線調準器5L‧‧‧片板6‧‧‧射束照射限制模10‧‧‧粒子線治療裝置Asa‧‧‧上游掃掠電磁鐵的掃掠軸(第1軸)Asb‧‧‧下游掃掠電磁鐵的掃掠軸(第2軸)PS‧‧‧穿透形狀PSa‧‧‧第一軸(ASa)的平面XB‧‧‧粒子射束的射束軸(EX入射到多片型射線調準器的射束之射束軸)
