The invention is directed to providing a technique for increasing a hold voltage of an electrostatic breakdown protection device having a bipolar transistor structure more than conventional and reducing the size of the device. A base region (a P impurity layer) is formed on a front surface of an epitaxial layer, an emitter region (an N+ impurity layer) is formed on the front surface of the P impurity layer, and the epitaxial layer and an N+ impurity layer form a collector region. A connected portion of a base electrode and the base region (the P impurity layer) is located between the end of the base region (the P impurity layer) on a collector electrode side and the emitter region (the N+ impurity layer). It means that the electrodes for the collector, the base and the emitter are formed in this order. The base electrode and the emitter electrode are connected through a wiring (not shown). A P+ isolation layer for dividing the epitaxial layer into a plurality of island regions is further formed.