A cooling and exhaust system of a dual oven has upper and lower ovens, in which, in one aspect, an installation structure of a cooling fan and an exhaust structure provided for respectively cooling and exhausting the upper and lower ovens may be integrated into a simplified structure having common components to increase the manufacturing productivity. In another aspect, fans provided at the upper and lower ovens may be independently controlled to operate at different speeds according to a desired operation to maximize the cooling efficiency.