To realize high performance vibration-damping properties to control wave absorption by arranging a controller near a fixing end which is positioned at a node of a vibration mode.

A force is applied in the orthogonal direction with respect to the longitudinal direction of an one-dimensional structural member. The force is computed by online computing by measuring the displacement of an action position of the force to make the equation of motion of the structural member differentiated with a position coordinate built in a computer be an input value. The action position of the force is located at the position apart from the fixed end by the differentiated width of the equation of the motion.