In the present invention, in an electromagnetic device that uses a coil current, such as a motor, an initial value of a desired coil current waveform is inputted, a magnetic field analysis is performed for the electromagnetic device, a power supply voltage waveform which is derived from a magnetic vector potential acquired from the analysis is calculated, and a circuit coupled magnetic field analysis is performed by using a fundamental waveform component of the calculated power supply voltage waveform, thereby providing a power supply voltage waveform calculation method and a circuit coupled magnetic field analysis method for obtaining a steady solution more quickly than in the conventional technique.