In a thermal head control method for thermally making a stencil master plate from a thermal stencil master plate sheet in the manner of a dot matrix for each line and forming an independent hole for each dot, a physical quantity representing the temperature of the thermal head, such as a time interval Ti for the plate making action by the thermal head for each line and a temperature actually measured from the thermal head, is measured before the plate making action of the next line. The measured temperature is compared with a prescribed value, and if the temperature is lower than the prescribed value, the thermal head is driven (pre-heated) at a power level which is lower than the rated power output and would not affect the thermal stencil master plate sheet. The effective heat emitting property of the thermal head is made uniform without regards to other factors, and a satisfactory perforation is carried out on a thermal stencil master plate sheet at all times.