Patent ID: 8153989

Claim:
A charged particle beam irradiating apparatus for continuously irradiating a charged particle beam along an irradiation line in an irradiation field that is set in an object, comprising: a scanning electromagnet that scans the charged particle beam; and a control unit that controls an operation of the scanning electromagnet, wherein the control unit changes a scanning speed when the charged particle beam is irradiated along the irradiation line such that a peripheral portion of a dose distribution of the charged particle beam is corrected, wherein the irradiation line extends in a rectangular wave shape, and includes a plurality of first irradiation lines that are arranged in parallel to each other at predetermined intervals and a plurality of second irradiation lines that connect the ends of adjacent first irradiation lines on one side or the other side, and wherein the control unit controls a scanning speed when the charged particle beam is irradiated along an outermost first irradiation line among the plurality of first irradiation lines to be lower than a scanning speed when the charged particle beam is irradiated along the other first irradiation lines.