A semiconductor light emitting element includes: a GaN substrate; a first semiconductor layer located above the GaN substrate and including a nitride semiconductor of a first conductivity type; an active layer located above the first semiconductor layer and including a nitride semiconductor including Ga or In; an electron barrier layer located above the active layer and including a nitride semiconductor including Al; and a second semiconductor layer located above the electron barrier layer and including a nitride semiconductor of a second conductivity type. The electron barrier layer includes: a first region having an Al composition ratio changing at a first change rate; and a second region having an Al composition ratio changing at a second change rate larger than the first change rate. In the first second regions, the Al composition ratio monotonically increases at the first change rate in the direction from the active layer toward second semiconductor layer.