Pendulor is a moving body type wave energy converter of efficient conversion with a caisson. Beside it, a simple Pendulor of no caisson installed in Tohoku Japan. The authors tried it to compare with the original one. The study concluded that the Pendulor with no caisson can do the same performance of the original one, if the no caisson type added with a mighty spring which recovers the resonant operation completely. The study discovered an attractive technology for cost saving of the wave energy.