A nitride-based semiconductor light-emitting device includes a light-emitting element having an n-GaN substrate and a nitride-based semiconductor multilayer film formed on the n-GaN substrate. The n-GaN substrate of the light-emitting element is fixed to a mount surface. The n-GaN substrate has one surface with the nitride-based semiconductor multilayer film formed thereon and an opposite surface with a metal layer and an ohmic electrode formed thereon. The metal layer contains a first metal and a second metal and the ohmic electrode is formed of the second metal. The adhesion between the ohmic electrode and the n-GaN substrate is thus improved. Accordingly, the semiconductor light-emitting device which is highly reliable with respect to the thermal strain from the mount surface can be provided.