The present invention provides a Group III nitride semiconductor light-emitting device in which the production method is simplified while migration of at least one of Ag atoms and Al atoms is suppressed, and a production method therefor. The production method comprises steps of forming a first electrode, forming a second electrode, and forming a second electrode side barrier metal layer on the second electrode. Moreover, the second electrode has an electrode layer containing at least one of Ag and Al. In forming the first electrode and the second electrode side barrier metal layer, the second electrode side barrier metal layer is formed on the second electrode while the first electrode to be electrically connected to the first semiconductor layer is formed. The first electrode and the second electrode side barrier metal layer are deposited are deposited in the same layered structure.