PURPOSE: To convert the kinetic energy of the vertical movement of waves into electric energy efficiency by positioning a tube body containing a magnetic- field generating means in the vicinity of the surface of the sea, and generating the electromotive force by the movement of seawater caused by the fluctuation of the water level in the tube associated with the vertical movement of the waves and the magnetic field formed with a magnetic-field generating means.

CONSTITUTION: In a hollow cylindrical tube body 12, whose upper and lower ends are opened, a power generating means 20 comprising electromagnets 21 and 21 formed of a pair of superconducting coils arranged at the facing positions of the tube body 12 in the diagonal directions and a pair of electrode plates 22 and 22 arranged at the position intersecting the like of the electromagnets at an approximately right angle is constituted. The power generating means 20 is arranged so that seawater flows in the approximately direct progressing direction with respect to both the line connecting both electromagnets 21 and 21 and the line connecting both electrode plates 22 and 22. Thus, the electromotive force is generated between the electrode plates 22 and 22. Therefore, the generated electromotive force is taken out through lead wires, and the electric power can be supplied.