To provide a device for controlling waves while converting the wave obstruction on the water surface to be applied to a water-surface structure to the pressure air or the pressure liquid so as to maintain the immovability of the structure and for utilizing the wave movement as the energy.

In order to support a structure 7 on the water surface, plural hollow gutters 8 are provided in the condition that a bottom part thereof is turned over, and an operating partition 9 to be moved with the wave is provided inside each gutter 8. A passage for sending the pressure air 10 generated inside the gutter 8 is provided in an upper part of the gutter 8, and divided to a filter device 6, a pressure air accumulator tube 3 and a pressure air communicating tube 2. Flow of the pressure air 10 to each device is controlled by a solenoid valve 5. In the case of controlling the wave movement, the valves to the pressure air accumulator tube 3 and the filter device 6 are closed. In the case of utilizing the wave movement as the energy, the valve to the pressure air communicating tube 2 is closed, and the valve to the pressure air accumulator tube 3 is opened and the valve to the filter device 6 is closed when the wave is moved upward, and the valve to the pressure air accumulator tube 3 is closed and the valve to the filter device 6 is opened when the wave is moved downward so as to take the air into the gutter 8.