In a conventional power circuit device, such as a power MOSFET monolithic integrated circuit device and a compound device, since five lead pins are lead out from the packaging with even intervals, sufficient separation distances between the third pin of a high voltage and other adjacent pins cannot be secured. According to this invention, the distances between the third pin and other adjacent pins are expanded so as to become wider than the distances between other pins. Furthermore, the third pin is formed into an upper position, its adjacent pins are formed into a lower position, and other pins are formed into a middle position. Thereby, sufficient separation distances between the third pin of the high voltage and other adjacent pins can be secured. Therefore, a structure favorable in terms of safety can be provided. Furthermore, by providing a full-mold packaging, the header portion is not exposed to assure an easy handling.