To provide a light-emitting element where electrons are efficiently injected into a Ge light emission layer and light can be efficiently emitted, the light-emitting element has a barrier layer 3 which is formed on an insulating film 2, worked in a size in which quantum confinement effect manifests and made of monocrystalline Si, a p-type diffused layer electrode 5 and an n-type diffused layer electrode 6 respectively provided at both ends of the barrier layer 3, and a monocrystalline Ge light emission part 13 provided on the barrier layer 3 between the electrodes 5, 6. At least a part of current that flows between the electrodes 5, 6 flows in the barrier layer 3 in a horizontal direction with respect to a substrate 1.