Abstract: A built-in microwave oven is provided, installed in the kitchen furniture as an integral part of the furniture. In the microwave oven, a suction grille and an exhaust grille are provided on the front wall of the external casing, and so cooling air is sucked and discharged through the front wall of the casing. Upper and lower heaters are installed within the casing, with an upper inside air passage formed around the upper heater that guide an air current formed by an upper heater cooling fan, and another air passage is formed around the lower heater that guides an air current formed by a lower heater cooling fan. The inflow air from the suction grille is partially and directly guided to the exhaust grille so as to be mixed with hot air from the upper and lower heaters prior to being discharged from the external casing to the atmosphere through the exhaust grille. Therefore, the exhaust air from the exhaust grille is preferably reduced in its temperature to a proper low point.

Abstract: The object of this invention is to provide a built-in microwave oven, installed in kitchen furniture as an integral part of the furniture. In the microwave oven of this invention, a suction grille (10) and an exhaust grille (20) are provided on the front wall of the external casing, and so cooling air is sucked and discharged through the front wall of the casing. Upper and lower heaters (32a and 32b) are installed within the casing, with an upper inside air passage (18a) formed around the upper heater (32a) for guiding an air current formed by an upper heater cooling fan, and another air passage (18a) is formed around the lower heater (32b) for guiding an air current formed by a lower heater cooling fan. The inflow air from the suction grille (10) is partially and directly guided to the exhaust grille (20) so as to be mixed with hot air from the upper and lower heaters prior to being discharged from the external casing to the atmosphere through the exhaust grille (20).