This invention provides a therapy planning apparatus comprising a scan path candidate extraction unit (22) for extracting a plurality of scan path candidates connected to all of the spot positions in one layer, in an evaluation function using a scan required time Tk of the k-th partial path in the partial paths of the paths between the adjacent positions of the spots on one of the plurality scan paths extracted from the scan path candidate extraction unit (22), a weighted coefficient wk, and the amount of the spot in the layer n, the weighted coefficient wk relative to the partial path passing through the affected tissue is set to 1, the weighted coefficient wk relative to the partial path passing through the normal tissue is set greater than 1, and the weighted coefficient wk relative to the partial path passing through the vital organs is set greater than the weighted coefficient wk relative to the partial path passing through the normal tissue.具備用以抽出連結一層內所有光點位置之掃描路徑之複數個候補的掃描路徑候補抽出部(22),在使用掃描路徑候補抽出部(22)所抽出之複數個掃描路徑中之一個掃描路徑上之相鄰之前述光點位置間之路徑的部分路徑中第k個部分路徑的掃描所需時間Tk、權重係數wk、及該層內之光點數量n的評估函數中,將對於通過患部組織之部分路徑的權重係數wk設定為1,將對於通過正常組織之部分路徑的權重係數wk設定為大於1,將對於通過重要臟器之部分路徑的權重係數wk設定為較對於通過正常組織之部分路徑的權重係數wk更大。1‧‧‧加速器2‧‧‧帶電荷粒子射束3‧‧‧射束傳輸系統4‧‧‧射束照射系統5‧‧‧X方向掃描電磁鐵6‧‧‧Y方向掃描電磁鐵7‧‧‧掃描電磁鐵8‧‧‧標的(患部)10‧‧‧照射控制裝置11‧‧‧掃描控制部20‧‧‧治療計劃裝置21‧‧‧光點位置記憶部22‧‧‧掃描路徑候補抽出部23‧‧‧掃描路徑評估部24‧‧‧掃描路徑決定部
