Abstract: Panel (10) for heating by an electric resistance obtained from a serpentine (55) of highly conductive material formed of a thin continuous strip of constant width, having a high ratio between width and thickness, that generates radiant heat by means of electromagnetic waves, placed inside a flat metal chamber (96) given a hermetic seal by continuous welds (90-95) along all its joins, obtained from a basic rectangular tray-shaped structure (11) and from similarly tray-shaped closing structures (80, 81) placed side by side in the basic structure (11).