Abstract: A HUD device includes a stepper motor, which rotates a reflection mirror for adjusting a display position of a virtual image. The stepper motor has an electric stabilization point and a mechanical stabilization point. A control system controls a drive signal for the stepper motor to change by a step angle at every predetermined period Ts in response to an adjustment instruction inputted from an adjustment switch. The control system continues to apply the drive signal until the electric stabilization point is attained even after the adjustment instruction is stopped to operate the stepper motor in a powered rotation mode. The stepper motor then operates in an inertia rotation mode toward the mechanical stabilization point is attained.