PROBLEM TO BE SOLVED: To provide a particle beam position stabilizer which simplifies beam track adjustment work.SOLUTION: A particle beam position stabilizer 40 has: at least two position sensors 42, 43 through which a particle beam passes； a center-of-gravity position calculation part 44 for calculating a position of the center of gravity of the particle beam； a beam position and angle calculation part 45 for calculating a beam incidence position and a beam incident angle from the calculated position of the center of gravity； steering electromagnets 41a, 41b for deflecting the beam incident angle； and a feedback control part 46 for calculating a correction value for the beam angle deflected by the steering electromagnets 41a, 41b from a deviation amount between the beam incidence position and beam incident angle calculated by the beam position and angle calculation part 45 and assumed beam target position and beam target angle, and outputting the correction value to the steering electromagnets 41a, 41b.SELECTED DRAWING: Figure 2
