PURPOSE: To provide a control method for input heat quantity in a sintering machine, by which the stable control can always be executed by restraining the variation of FeO content and yield.

CONSTITUTION: A first relation indicating the correlation between the output heat quantity of raw material charged to the sintering machine and the FeO content contained in the sintered product 3 and/or a second relation indicating the correlation between the above output heat quantity and the yield of the product 3 are obtd. beforehand. The actually measured value of the above output heat is applied to the above first relation and/or the second relation to calculate the predicting value of the above FeO content and/or yield. The input heat quantity supplied to the sintering machine is controlled based on the difference between the calculated prediction value of the FeO content and/or yield and the aimed value thereof. By this method, the stable control can always be executed.