Provided is a method of controlling a heating cooking apparatus that involves accurate heating processing of food by one sequence and can prevent even underheating while preventing overheating by using only a humidity sensor if the food has a weight within a given weight range. When a generated steam volume at a forced finish time T.sub.n-1 found on the basis of a minimum amount-minimum steam curve does not reach even a minimum steam volume B.sub.1 found on the basis of a slowly rising maximum amount-maximum steam curve, the generated steam volume is smaller than in the case of a food having a maximum weight. Therefore, it can be judged that the food is not housed in a heating chamber and that heating is performed in a no-load condition with an exceedingly small generated steam volume, and the operation of the heating cooking apparatus is forcedly stopped. When a generated steam volume at a maximum detection time T.sub.m+1 does not reach even a standard steam volume A found on the basis of a maximum amount-maximum steam curve, it is judged that a large amount of food exceeding a maximum amount is to be heated and the operation of the heating cooking apparatus is forcedly stopped.