A laser diode device comprises an n-type cladding layer containing aluminum (Al); an active layer containing indium (In), gallium (Ga) and nitrogen (N); and a codoped layer that is provided between the substrate and the n-type cladding layer. The codoped layer is also containing gallium (Ga) and nitrogen (N), and is codoped with one of silicon (Si) and germanium (Ge) as impurity working as a donor and one of magnesium (Mg) and zinc (Zn) as impurity working as an acceptor.