A 3D model generating system for accurately estimating a shape of an entire space surrounded by a plurality of surfaces is provided. Image acquiring means of the 3D model generating system acquires a plurality of images respectively capturing different directions in a space surrounded by a plurality of surfaces. Partial model generating means generates a plurality of partial models respectively corresponding to the images, each of the partial models representing a portion of the surfaces captured in the images. Overall model generating means generates an overall model representing an entire surface based on the partial models generated by the partial model generating means.