To obtain a method and an apparatus which generate a power in a high efficiency without using a seed material.

In the method of generating the power, an MHD power generation or a magnetic field concentration type power generation is performed by using a high temperature conductive gas obtained by irradiating an impact wave to a gas in a furnace, generated in a waste incinerator or a melting furnace. The MHD power generation or the magnetic field concentration type power generation is performed by extracting the part or all of the gas in the furnace, generated in the waste incinerator or the melting furnace out of the furnace, and using the high temperature conductive gas obtained by irradiating the impact wave to the gas in the furnace, and removed out of the furnace.