A light-emitting device has two light-emitting element. In a substrate portion of the light-emitting device having a first internal positive electrode connected to the positive electrode side of a first light-emitting element, a first internal negative electrode connected to the negative electrode side of the first light-emitting element, a second internal positive electrode connected to the positive electrode side of a second light-emitting element, and a second internal negative electrode connected to the negative electrode side of the second light-emitting element, these electrodes are provided so that homopolar electrodes are disposed diagonally.