PURPOSE: To cause an air stream from a wave in a ventilation pipe and use the air stream for power generation, by arranging a pair of or plural pairs of flexible air chambers to the forward direction of the wave under the level of water at a distance in integral multiplex of half wave length and communicating the air chambers of each pair through the ventilation pipe.

CONSTITUTION: An example of arranging a pair of flexible air chambers 1, 2 is shown in the drawing, in which the chambers are arranged with a distance of half wave L/2 of the wave length L and communicated by a ventilation pipe 5. The numeral 6 is a generator chamber in which a one-way commutating valve and air turbine are assembled. When a wave is positioned as shown in the drawing, a crest of the wave is located above the air chamber 1, then the air chamber 1 is applied with a water head larger than a water head applied to the air chamber 2 located below a trough of the wave, and the air chamber 1 is compressed as shown by a full line, reversely the air chamber 2 is inflated, then air in the ventilation pipe flows to the direction of an arrow head, if the wave is reversely positioned, the air flows to the direction of an inverse arrow head, in this way, movement of the air stream is utilized to perform electric power generation.