A parking assistance device for aligning a vehicle coil (11) mounted on a bottom surface of a vehicle (10) with a ground coil (31) installed on a ground, detects a voltage of the vehicle coil (11), detects a change in the voltage detected, notifies a driver of first braking when the change in the voltage detected shifts from an increasing direction to a decreasing direction, and notifies the driver of second braking when the change in the voltage shifts from the decreasing direction to the increasing direction.