A nitride semiconductor device such as a light emitting device in which an active layer is formed between an n-type semiconductor region consisting of one or more nitride semiconductor layers and a p-type semiconductor region consisting of one or more nitride semiconductor layers, characterized in that at least one of the nitride semiconductor layers of the p-type semiconductor region or the n-type semiconductor region is a super-lattice layer consisting of layer-built 1st layers and 2nd layers made of nitride semiconductors whose compositions are different from each other. By the above mentioned construction, the operating current and operating voltage of the device are lower and the efficiency of the device is improved.