Control method of stepper-motor

The present invention provides a method of controlling a stepping motor, by a first determined from Table CPU1 supply current value, and sends a signal to the motor driver in order to supply current value supplied to the excitation phase A, B. And, the CPU 1 is determined according to the load torque current integral value in each excitation phases A, B, and also reads out the difference value between the desired load torque and a rotational torque from the ROM 7, and the load torque is determined relative to the most good rotation torque. CPU1 reads out the current value from the second data table based on the determination result, and transmits a corresponding signal to the current control circuit.