To obtain a gravitational force point conversion type power engine by making it possible for a device to continue to rotate by letting the device automatically produce the difference between driving torque and braking torque in rotation in one and the same gravity field.

A gravitational force point conversion type power engine is structured such that it is allowed to rotate by so designing same that the force acted force point part is situated outside in rotation driving and inside in rotation braking when an axis 2 of a rotary elongated bar 1 tilts for converting the gravity to a torque using such differential torque.