In particle beam irradiation equipment (100), a control unit (2) causes a storage unit (3) to store, as position information of reference positions, position information of electromagnets (1, 1A, 1B) that is acquired at the time of their first alignment, by cameras (10, 10-1, 10-2, ···, 10-n), and then acquires displacement amounts, based on the position information of the reference positions stored in the storage unit 3 and from position information of the electromagnets (1, 1A, 1B) acquired at the time of their realignment, by the cameras (10, 10-1, 10-2, ···, 10-n).
