A new IGBT has been developed for Toyota’s 4th generation HV’s. The power loss reduction of power control units (PCUs) for hybrid vehicles (HVs) is essential to improve their fuel efficiency. It is important to reduce the loss of the power devices (IGBTs and FWDs) used in the PCUs, because of being about 20% of the whole power loss of the HVs. Also the trade-off between the power device downsizing and the heat dissipation feasibility is the important technical issues. In order to achieve the 4th generation PCU design goal, the IGBT development goal is to improve 19.8% of the losses, 30% of downsizing, 14% of the breakdown-voltage than the previous generation. For the loss reduction goal, SBL (Super-Body-Layer) structure is installed to improve the trade-off characteristic between the switching loss and the steady-state loss. The goal is achieved by optimizing the SBL impurity concentration which is an important parameter for trade-off characteristic improvement. For downsizing of the IGBT, an environment friendly surface electrode structure is designed to realize a double-sided cooling system. Thus, the heat dissipation feasibility for the high current density due to downsizing has been established. Also, RESURF (Reduced-SUrface-Field) structure is adopted for the edge termination structure. Although the idea is already well known, a new structure of the RESURF has been established for both high breakdown voltage and high reliability. The optimum balance of RESURF impurity concentration has contributed to higher breakdown-voltage and downsizing. The loss reduction and the downsizing, combined with the improvement of breakdown-voltage of the IGBT has been achieved. This development contributes to the loss reduction and downsizing of 4th generation PCU, and to Toyota’s 4th generation HV’s high fuel efficiency.