To rise a steam temperature without rising a pressure of saturated steam to superheated steam by taking magnetic force of an electromagnetic induction coil in the bilateral direction, and heating a heated object opposed to the electromagnetic coil together.

The electromagnetic induction coil is charged, and the coil is held from both faces by the heated object opposed to the electromagnetic induction coil at two faces. The magnetic force is reacted on the heated object with an opposing or surrounding structure, and the temperature of saturated steam is raised by making the steam pass in the heated object in a state where the steam pressure is not raised.