A gallium nitride-based compound semiconductor light-emitting device is disclosed which includes an n-type semiconductor layer of a gallium nitride-based compound semiconductor, a light-emitting layer of a gallium nitride-based compound semiconductor and a p-type semiconductor layer of a gallium nitride-based compound semiconductor formed on a substrate in this order, and has a negative electrode and a positive electrode provided on the n-type semiconductor layer and the p-type semiconductor layer, respectively. The negative electrode includes a bonding pad layer and a contact metal layer which is in contact with the n-type semiconductor layer, and the contact metal layer is composed of a Cr--Al alloy.