A likely value is calculated by a maximum-likelihood method for all coefficients of a relative error correction circuit network model derived by assuming that, for all pairs of two ports selected from among signal line ports related to application or detection of a high frequency signal and non signal line ports other than the signal line ports, there exists a leak signal directly transferred between the ports. A coefficient of a first relative error correction circuit network submodel derived by assuming that, for all pairs of two ports selected only from among signal line ports, there exists a leak signal directly transferred between the ports, and a coefficient for a non signal line port of a second relative error correction circuit network submodel derived by assuming that there exists a signal reflected at a non signal line port are used as initial values.