To enhance an efficiency, and thereby obtain its great output by letting electricity be included in the cycle of a thermal engine, and transforming one thermal source into equivalent works.

A stationary electrode 4 is mounted in the inner bottom wall surface of a piston cylinder 1, and a movable electrode 5 is mounted in the inner surface of an opposite piston 2. The voltage of 1KV per interval, for example, is applied in between both the electrodes 4 and 5 when there exists the pressure P of energy cycle at the point (W), and gas is thereby electrically charged, and similarly let shortcircuiting develop between both the electrodes 4 and 5, and the afore-said gas is thereby discharged. In electrically charged working medium in the piston cylinder 1, the direction of dipole moment for each molecule consisting of gas for example, is arranged in one direction, as a result, heat is thereby generated, and the pressure (X) of energy cycle is increased up to an '0' point. Subsequently gas is adiabatically expanded, and when its pressure comes to a point (W), the temperature of gas is lowered down, and its pressure thereby comes to a point (Y).