It is confirmed that more electric society is right direction toward sustainable growth achievement. Electronics including power electronics which enables efficient energy usage is important key technology for the society. Nega-watt cost concept, as an index of development, is proposed to promote efficiency improvement and prevalence of the next generation power electronics (PEs). Improvement of power density and watt cost are key factors for nega-watt cost down. Seed technologies are discussed from system integration point of view. In terms of manufacturability, the importance of high quality wafer supply is mentioned. Finally strategies of Japan for the PEs are referred.