NOVELTY - The method involves coupling airtight motive power cycle (15) and a heat pump (HP) thermally. An electric power-gas generator (42) is heated to predetermined temperature with a pulse power. The high-temperature/high pressure power gas is generated by making the high-temperature/high pressure working fluid contact with an electric power-gas generator. A movable piston (200) is operated with high-temperature/high pressure power gas, for generating mechanical energy. The mechanical energy is supplied to a generator (16) through an output shaft, for generating the electric power.    USE - Geothermal energy method for generating electric power.    ADVANTAGE - The electric power is generated by supplying this mechanical energy to the generator, so that the geothermal energy of underground remaining-layer portion or stratum surface vicinity in the unused state is used effectively, thus the expenses and construction period for the excavating work are reduced, the environmental disruption is prevented, and the electric power generation is achieved at low cost. The installation area for the apparatus is reduced, and the apparatus is operated safely and reliably.    DETAILED DESCRIPTION - The heat pump is provided to generate the coolant steam from the liquefaction refrigerant through a geothermal recuperator (2) using the geothermal heat of the underground remaining-layer portion or stratum surface vicinity. A low-temperature low-pressure working fluid is compressed with a fluid compressor (27), and a high-temperature/high pressure working fluid is generated. The electrical storage electric power of an electrical storage unit (20) is supplied to a pulse power supply (28), and a pulse power is generated. An INDEPENDENT CLAIM is included for a geothermal energy apparatus.    DESCRIPTION OF DRAWING(S) - The drawing shows a circuit block diagram of the geothermal energy apparatus. (Drawing includes non-English language text)    Geothermal recuperator (2)    Airtight motive power cycle (15)    Generator (16)    Electrical storage unit (20)    Fluid compressor (27)    Pulse power supply (28)    Electric power-gas generator (42)    Movable piston (200)