The neutron emission unit is configured to emit neutrons such that a center axis (Nh) of neutron emission intersects a center axis direction of collimators (23a to 23e). A calculation unit is capable of generating information about an inspection object in the center axis direction of the collimators, based on position information of the neutron detector and/or position information of the neutron emission unit, information about an angle (θ1) at which the center axis of the neutron emission intersects the center axis direction of the collimators, and a neutron amount detected by the neutron detector.