From the power loss reduction and safety operation points of view, the direction of power device developments is simply one-way. However, from the application point of view, the direction is wide-ranging. There are a variety of requirements to be considered, such as switching waveforms, operational environments including not only the temperature range but also the combination of the humidity, the cosmic ray endurance, the package compactness and so on. In this study, several efforts are explained as the latest technologies.