Abstract: A neutron detection element 100 includes: a neutron detector configured to detect a neutron and convert the neutron into an electrical signal; and an amplifier configured to amplify an output of the neutron detector. The neutron detector includes: a semiconductor layer of a first conductivity type; a detector diffusion layer of a second conductivity type in the semiconductor layer; and a neutron conversion layer on the detector diffusion layer. The neutron conversion layer converts a neutron into an ?-ray. The amplifier includes a plurality of transistors in the semiconductor layer. The neutron conversion layer is a metal film including a layer containing boron 10 or a layer containing lithium 6.