To prevent a malfunction of a thermostat attached to a heater panel.

The thermostat 40 for cutting the energization to a heater 33 in emergency is attached to the upper position inside a warm air duct 31 between a pair of heater panels 30B and 30C with a cord heater 33, by a bracket 50. Heat storage plates 60 and 65 having large heat capacity are clamped between a temperature detecting part 41 of the thermostat 40 and the bracket 50, and an air guide 75 sending a part of the air led from a heating cabinet 18 to the thermostat 40 is provided. When shutting off the power supply during heating storage operation, the temperature in the surroundings of the thermostat 40 rapidly increases, however, the heat from the bracket 50 is stored by the heat storage plates 60 and 65, and the thermostat 40 itself receiving the air led from the heating cabinet 18 becomes a low temperature during the heating storage operation, so that the temperature transmitted to the temperature detecting means 41 does not rise so much compared with that in the surroundings and is retained at an operation temperature or less.