The objective is to obtain a respiratory induction apparatus and a particle beam therapy system in which respiration can appropriately be induced by accurately evaluating the respiration. There are provided a respiratory induction control unit (7cC) that generates a desired respiratory signal (R tj (t)) for respiratory induction a real respiration measurement unit (7a) that outputs a real respiratory signal (R rl (t)) obtained by measuring real respiration of a patient and a respiration evaluation unit (7cE) in which by, as a unit, utilizing data of a single period (T res ) of the desired respiratory signal (R tj (t)), there is calculated a pair of coefficients (a 1 and b 1 ), of trigonometric functions, which correspond to the 1st-order terms at a time when Fourier series expansion is applied to data of the desired respiratory signal (R tj (t)) and data of the real respiratory signal (R rl (t)), which is acquired in synchronization with the data of the desired respiratory signal (R tj (t)), and there are performed comparisons between the respective gains (G tj and G rl ) and between the respective phases (Æ tj and Æ rl ), which are obtained from the coefficients (a 1 and b 1 ), so that there is evaluated a misalignment of the real respiration from the desired respiratory signal.
