Semiconductor device with extra control wiring for improving reverse breakdown voltage

In a lateral bipolar transistor, a control wiring layer is laid down under an emitter electrode wiring layer, and a voltage according to a reverse bias voltage applied to the collector diffusion layer is applied to the control wiring layer, thereby preventing the occurrence of a leakage current from the emitter diffusion and further the flow of the leakage current to the device isolation region, even under a situation that a certain reverse bias voltage is applied to the collector of the transistor.