A method and apparatus for controlling an electric discharge machine wherein a motor (105) for establishing relative movement between an energized electrode (EP) and a workpiece is driven in accordance with command data (101). The method includes the steps of converting commanded speed information into a speed command value (VA) to control the speed of the motor (105), counting, by means of a counter (107), pulses generated by a sensor (106) each time the motor (105) rotates by a predetermined amount, reading the value of the count in the counter (107) periodically, adding the read values cumulatively to determine the present position of the electrode (EP), and sending a command to the counter (107) each time its counted value is read, to cancel the counted value.