A parking assistance device, comprising: - an imaging means mounted on a vehicle to image a periphery of the vehicle; - a coil for the vehicle installed on a bottom surface of the vehicle; - a displaying means configured to display an image imaged by the imaging means; and - a controlling means configured to perform a display control on the displaying means, wherein the controlling means is configured: - to store a parking initial image imaged by the imaging means and simultaneously showing a power transmission coil installed on a road surface in a parking space and a ground mark (41, 42) provided on the road surface and at a predetermined distance from the power transmission coil, - to estimate a position of the power transmission coil according to a parking final image indicating the ground mark (41, 42) imaged by the imaging means and the parking initial image when a distance between the vehicle and a target parking position falls below a predetermined value and the power transmission coil disappears from the imaging means, - to display an image showing the power transmission coil on the displaying means according to the estimated position of the power transmission coil, - to superpose and to display an image indicating the coil for the vehicle on the displaying means, and - wherein said position of the power transmission coil that is estimated according to the parking final image indicating the ground mark (41,42) imaged by the imaging means and the parking initial image is estimated by said controlling means J Z based on a distance between the ground mark (41, 42) and the coil for the vehicle on the parking final image and on a distance between the ground mark (41, 42) and the coil for the vehicle on the parking initial image, and wherein the target parking position is a parking position for the vehicle, where the power transmission coil installed on a road surface and the coil for the vehicle installed on the bottom surface of the vehicle overlap each other. - an imaging means mounted on a vehicle to image a periphery of the vehicle; - a coil for the vehicle installed on a bottom surface of the vehicle; - a displaying means configured to display an image imaged by the imaging means; and - a controlling means configured to perform a display control on the displaying means, - to store a parking initial image imaged by the imaging means and simultaneously showing a power transmission coil installed on a road surface in a parking space and a ground mark (41, 42) provided on the road surface and at a predetermined distance from the power transmission coil, - to estimate a position of the power transmission coil according to a parking final image indicating the ground mark (41, 42) imaged by the imaging means and the parking initial image when a distance between the vehicle and a target parking position falls below a predetermined value and the power transmission coil disappears from the imaging means, - to display an image showing the power transmission coil on the displaying means according to the estimated position of the power transmission coil, - to superpose and to display an image indicating the coil for the vehicle on the displaying means, and - wherein said position of the power transmission coil that is estimated according to the parking final image indicating the ground mark (41,42) imaged by the imaging means and the parking initial image is estimated by said controlling means J Z based on a distance between the ground mark (41, 42) and the coil for the vehicle on the parking final image and on a distance between the ground mark (41, 42) and the coil for the vehicle on the parking initial image, and