This article proposes an optimization design procedure for the switching waveform considering a bus bar geometry. In this proposed procedure, three items - the surge voltage, damped oscillation, and switching loss - are evaluated to achieve user-defined design objectives for realizing the optimized switching waveform. This study targets a bus bar geometry for high-speed switching using wide band-gap devices; thus, parasitic parameters in the power converter are considered. The parasitic parameters, which are the inductance, capacitance, and ac resistance, of the bus bar are analyzed by finite element analysis because it should be discussed the frequency characteristics for realizing the optimum switching waveform. The experimentation is performed using buck converter circuits, rated at 400 V and 30 A. As a result, the surge voltage, damped oscillation, and switching loss are, respectively, reduced 13.2%, 49.7%, and 29.7% with respect to user-defined design objectives, simultaneously.