Disclosed is a method including: calculating power supply input impedance of the LSI from the number of output buffers of the LSI, output impedance of an output buffer, signal characteristic impedance and characteristic impedance of power supply/ground of an LSI terminal, a package, and a chip terminal part, characteristic impedance of wiring connected to an LSI output terminal, and output signal damping resistance calculating a reflected voltage of power supply noise at a semiconductor device mounted on an electronic circuit board, based on impedance characteristic between a power supply and ground of the semiconductor device; and analyzing power supply noise of the electronic circuit board, based on the reflected voltage of the power supply noise at the semiconductor device.