Abstract: A beam target for generating a nuclear reaction product by irradiation with a beam obtained from a beam generation source includes a cone body which has a tapered inner surface which is reduced in diameter toward a tip, and supply means for supplying liquid metal to the inner surface of the cone body to form a liquid film of the liquid metal on the inner surface. It is possible to form the liquid film of the liquid metal on a cone body surface to increase an irradiation area of the beam, and also dispose a target substance such as LLFP around the cone body, and hence it is possible to efficiently use the nuclear reaction product (e.g., a neutron) generated by beam irradiation of the liquid metal.