In this paper, model experiments were conducted in regular and irregular waves for the twin-hull-type floating wave energy converter equipped with some electric generators. The results of generated electric power, motion of the converter and transmitting wave obtained by the experiments were compared with the ones predicted by theoretical method. It was found that the results obtained by the experiments were in agreement with the predicted values. Further, the average values of generated electric power and the rate of operation of the full scale wave energy converter ( Δ =1, 430 ton) were estimated by using the experimental data and actual wave data for some coastal areas of Japan. The average electric power and the rate of operation were respectively estimated to have about 40 kW and 97 percent throughout the year at Habu, which was located on the Pacific side of Japan.