seventh aspect of the invention is characterized in that the noise waveform supplying step is a step of supplying a start point power noise waveform to the power terminal in a circuit for analyzing the inter-block power wiring created from the impedance information and that the power noise waveform calculating step includes an inter-block power noise calculating step of obtaining an inter-block power noise waveform at each internal node point in the circuit for analyzing the inter-block power wiring as well as obtaining a block terminal power noise waveform at a terminal in each functional block and an intra-functional-block power noise waveform calculating step of obtaining a functional block power noise waveform at each node point in the functional block as well as obtaining an element terminal power noise waveform at the power terminal in each element by providing as input the block terminal power noise waveform to the impedance circuit in the functional block