The stepping motor controller comprising an excitation signal generator, a switching circuit, a PWM constant current control circuit and a current sensor further comprises a motor detector circuit that transmits a control signal for generating a constant current for a predetermined time for detecting the motor, a constant current generator that receives the control signal and generates the constant current to be supplied to the winding, a reference voltage generator that generates a reference voltage, a voltage comparator circuit that compares the reference voltage with a voltage drop at the winding, and a current value setting signal generator circuit that transforms an output of the voltage comparator circuit into a current value setting signal for the PWM constant current control circuit. An output of the current value setting signal generator circuit is connected to a current value setting terminal of the PWM constant current control circuit.