Provided are an electron beam curable resin composition including an olefin resin, a crosslinking agent, and a white pigment, in which the crosslinking agent has a saturated or unsaturated ring structure, at least one atom among atoms forming at least one ring is bonded to any allylic substituent of an allyl group, a methallyl group, an allyl group through a linking group, and a methallyl group through a linking group, and the white pigment is blended in an amount of more than 200 parts by mass and 500 parts by mass or less with respect to 100 parts by mass of olefin resin, a reflector resin frame using the resin composition, a reflector, a semiconductor light-emitting device, and a molding method using the resin composition.