In order to improve the operationality of a walk-through system using panorama photography images, the system is provided with a view calculating unit for calculating view information in accordance with a user instruction from an operation unit, the view information including view position information and view direction information; a panorama image storing unit for storing a plurality of panorama images; a path storing unit for storing path information of the panorama images; an advancable path calculating unit for calculating advancable path information at a next dividing point in accordance with the view information and the path information; and an image generating unit for generating a cut-out image from the panorama image in accordance with the view information, generating a sign figure representative of the advancable path in accordance with the advancable path information, and synthesizing the cut-out image and the sign figure to generate a display image.