PURPOSE: To enable to shorten the rise time of a cooker by a method wherein both a grill heater provided at the upper part of a heating chamber and a hot air circulating heater provided outside the heating chamber are simultaneously energized only during the period of time until the temperature in the heating chamber reaches the cooking set temperature.

CONSTITUTION: During the hot air circulating mode, an air heater 5 is energized so as to send the heated air in an oven 2 by means of a hot air fan 6 in order to raise the temperature in the oven 2. However, at the rise time of the mode, a grill heater 8 is also energized at the same time. Though the temperature in the oven 2 does not rise before the temperature onto the wall surface in the oven 2 because the hot air flows along the wall surface in the oven 2, the grill heater 8 can directly heat the air in the oven because the grill heater is attached at the upper part in the oven 2, resulting in enabling to shorten the rise time by the time assisted by heating with the grill heater. At the rise time of the combination cooking mode, an electronic range is turned OFF before the temperature in the oven 2 reaches the set temperature, because the input power may be too large if the hot air heater 5, the grill heater 8 and the electronic range are simultaneously turned ON.