To suppress abnormal scanner control due to CPU reset during scanner driving and improve effectiveness thereof.

This scanner motor controller, including a control circuit which controls driving and stopping of a motor 12 driving a document scanning scanner and involves a CPU reset by a reset signal and a monitor circuit 10 which monitors power supply voltage Vcc for generating a reset signal when the voltage drops below the prescribed value, is provided with monitoring circuits 11, 10 which generate the first signal S1=L if the voltage Vcc drops below the first prescribed value Vref1 and the second signal S2=L if it drops below the second prescribed value Vref2 lower than the first prescribed value Vref1. The CPU conducts stopping control in response to the first signal S1=L during driving the motor and is reset by the second signal S2=L. The first signal S1=L is applied to an interrupt port INT B, and the CPU 14 conducts stopping control by interrupt processing. The first signal S1=L is applied to the interrupt port with the highest priority.