A non-destructive inspection device 10 using backscattering of neutrons includes a neutron source 3 that radiates a pulse neutron beam to a surface 1a of an inspection target 1, a neutron detection device 5 that detects scattered neutrons scattered in the inspection target 1 and returned, and a measurement device 7 that measures the detection number of scattered and returned neutrons detected by the neutron detection device 5 and generates detection number data expressing the detection number with respect to time.