A bipolar transistor at least includes a semiconductor substrate including an N− epitaxial growth layer and a P− silicon substrate, an N+ polysilicon layer, a tungsten layer, two silicide layers, a base electrode, an emitter electrode, and a collector electrode. The N+ polysilicon layer formed on the semiconductor substrate is covered with one of the silicide layers. The tungsten layer that is formed on the silicide layer is covered with the other silicide layer.