PURPOSE: To perform accurate control of the temperature of the interior of an oven by a method wherein a temperature sensor is mounted to the side plate of an oven frame body, vent pores are formed in the side plate, and a sensor cover member is mounted to the outside of the side plate in a manner to cover the temperature sensor and the vent holes therewith.

CONSTITUTION: A temperature sensor 9 is mounted to a plate 3b, positioned opposite to a discharge hole 8, of an oven frame body 3 in a state to protrude into an oven 2. A number of vent pores 11 like those of a panting plate are formed in the side plate 3b to which the temperature sensor 9 is positioned. A sensor cover member 12 is mounted to the outside of the side plate 3b, in which the vent pores 11 are formed, in a manner to cover the temperature sensor 9 and the vent pores 11 therewith. Even when the open air reversely flows in a case body 1 by the influence of a ventilating fan and natural air, the sensor cover member 12 causes prevention of exercising an influence on the temperature sensor 9 by the open air, and temperature in the oven 2 can be controlled accurately.