A nitride light emitter includes: a nitride semiconductor light-emitting element including an AlxGa1-xN substrate (0≤x≤1) and a multilayer structure above the AlxGa1-xN substrate; and a submount substrate on which the nitride semiconductor light-emitting element is mounted. The multilayer structure includes a first clad layer of a first conductivity type, a first light guide layer, a quantum-well active layer, a second light guide layer, and a second clad layer of a second conductivity type which are stacked sequentially from the AlxGa1-xN substrate. The multilayer structure and submount substrate are opposed to each other. The submount substrate comprises diamond. The nitride semiconductor light-emitting element has a concave warp on a surface closer to the AlxGa1-xN substrate.