PURPOSE: To limit flow of a current only in a forward direction of a diode of an output transistor at the time of applying static electricity by using a high breakdown voltage logic circuit controlled by a logic circuit and operated by a second power source voltage.

CONSTITUTION: The high breakdown voltage semiconductor integrated device comprises a logic circuit to be operated at least by a first power source voltage and a high breakdown voltage logic circuit to be controlled by the previous logic circuit and to be operated by a second power source voltage. One or more high breakdown voltage diodes 27 each having an area larger than a drain area of a high breakdown voltage to be used in the high breakdown voltage logic circuit are disposed between the second power source voltages. A cathode of the diode 27 is connected to a positive side potential of the second power source voltage, and an anode is connected to a negative side potential. If static electricity is applied, a current flows in a route of an arrow with a solid line 28. Thus, an effect that a current only in a forward direction flows to a diode 21 of an output transistor is provided.