Embodiments relate to a bipolar junction transistor and a method for manufacturing the same. An oxide pattern may be formed on a P type semiconductor substrate. A low-density N type collector area may be formed in the semiconductor substrate. First spacers may be formed at sidewalls of the oxide pattern, and a low-density P type base area may be formed in the semiconductor substrate. Second spacers may be formed on sidewalls of the first spacers. A high-density N type emitter area may be formed in the low-density P type base area between the second spacers, and a high-density N type collector area may be formed in the semiconductor substrate at an outside of the first spacers. The bipolar junction transistor may be realized through a self-aligned scheme using dual nitride spacers. A base width between the emitter area and the low-density collector area may be narrowed by the width of the second spacer.