PURPOSE: To prevent foods from being affected by its surrounding temp. when the foods to be cooked are classified according to the amount of alcohol contained therein by a method wherein the longer the identifying time of a control device is set, when the lower the surrounding temp. detected by a temp. sensor is.

CONSTITUTION: A control device 20, upon receiving an instruction of automatic cooking, reads room temperature t0 by a temp. sensor 19 and obtains the identifying time T (j) by computation based on the room temp. t0, i.e., from the operation expression T (j)=67-1.4 t0 in the variables of room temp. t0. This operation expression is so formulated as to lengthen the identifying time with decreasing room temp. t0 and established based on the results from a number of tests. This permits the identifying time to be likewise lengthened, even when the amount of the alcohol escaping from the pizza containing a large amount of the alcohol decreases with decreasing room temp.