PURPOSE: To provide a heating cooking apparatus wherein an object to be cooked is properly heated and cooked even if the reflectivity of a heater reflection plate is lowered, by the formation of an oxide film on the surface of the heating reflection plate.

CONSTITUTION: A controller reads cumulative cooking time (step S1), and calls for the reflectivity of a heater reflection plate based upon the cumulative cooking time (step S2), and further calculates a correction coefficient from the reflectivity (step S3). Successively, the controller estimates corrected cooking time from the correction coefficient (step S4), and thereafter executes heating cooking (step S5) and adds the cumulative cooking time (step S6). thus, one time heating cooking time is corrected according to the cumulation of the number of times of the heating cooking, so that the amount of heating to the object to be cooked is kept unchanged.