<p>A seat heater (10) is provided with the following: a seat-warming heater (1) that is connected to a power source (5) and is for warming an occupant seated on a seat; an overheating prevention section (2) for releasing the connection between the seat-warming heater (1) and the power source (5) to prevent overheating of the seat-warming heater (1) when the heating reaches a predetermined temperature; and an overheating prevention section heating- heater (3) for heating the overheating prevention section (2). The overheating prevention section (2) is of a non-return type, and the overheating prevention section heating-heater (3) is disposed so as to cover an opposing portion of the overheating prevention section (2). This makes it possible to succeed in both raising output and improving safety.</p>
