Provided is a neutron capture therapy system including: an irradiation room in which a patient is irradiated with a neutron beam； a neutron beam output portion which irradiates the inside of the irradiation room with the neutron beam； a recessed groove portion (61) which is provided on a floor surface (F) of the irradiation room； a guide rail (62) which is provided in the recessed groove portion (61) so as to extend along the recessed groove portion (61) ； a belt (BT) which is disposed in the recessed groove portion (61) so as to cover an upper surface of the guide rail (62)； and a treatment table (80) capable of moving along the guide rail (62). The treatment table (80) has a lifting roller (82c) that partially lifts the belt (BT), which is positioned in the recessed groove portion (61), above the recessed groove portion (61). An upper surface of a portion of the belt (BT) which is not lifted above the recessed groove portion (61) by the lifting roller (82c) constitutes a substantially identical surface to the floor surface (F).
