From design information on a circuit board a wiring designation unit designates a wiring model for signal analysis. A first analysis unit generates, through a 3-D electromagnetic analysis, a first output waveform received at a receiving end of a wiring model when a first input signal pattern changing from 0 to 1 is input to a sending end of the wiring model. A second analysis unit generates, through the 3-D electromagnetic analysis, a second output waveform received at the receiving end of the wiring model when a second input signal pattern changing from 1 to 0 is input to the sending end of the wiring model. An output waveform generation unit selects the first output waveform at bit 1 of a random signal of about 100 bits and selects the second output waveform at bit 0 thereof to generate for a predetermined bit count the first output waveform or the second output waveform selected with each bit position as a starting point. An output waveform synthesis unit synthesizes the output waveforms for the bit count to generate an output waveform received at the receiving end when the random signal is input to the sending end of the wiring model.