PURPOSE: To carry out safe and economical floor heating by a method wherein a floor is formed with electrically conductive boards, each of which is provided with a heat generating ring and, in its neighborhood, a rotary unit on which permanent magnets are mounted. These features can generate heat out of the heat generatong ring by inducting eddy currents.

CONSTITUTION: A prt of a floor is constituted with several sheets of electrically conductive boards 1 which are square plates of aluminum or other materials. A heat generating ring 2 is fixed at the center of the conductive board 1, on underside of which a rotary unit 3 is mounted with a rotating shaft 5. Permanent magnets 4a, 4b are fixed on the external periphery of the rotary unit 3. Rotation of the rotary unit 3 causes the permanent megnets 4a, 4b to rotate continuously so as to induce eddy currents in the heat generating ring 2 for heat generation. Heat generated in the heat generating ring 2 is transferred to the conductive boards 1 for floor heating.