To provide a safe and efficient vibration test capable of preventing an excitor from being driven by discontinuous command signals so as not to apply harmful impact to a specimen, even when an operator changes optionally an amplitude, a frequency or an offset value of the command signal during excitation.

This method has a function for generating a command signal under an excitation condition after change by requiring a transition state of a fixed time, so as not to apply an impact which is not under a desired excitation condition to the specimen, when the operator changes the amplitude and the frequency of the excitation condition, while driving the excitor with a sine wave signal by an input means. In the transition state, the amplitude or the frequency is increased at the rate determined by dividing a differential value between the front and rear of the change thereof by a fixed time.