A structure forming method of present invention includes a first step including forming a first pattern serving as a fine pattern using an electromagnetic wave thermal conversion material on a first surface, on the side on which an expansion layer which expands by heating is provided, of a medium including the expansion layer and then irradiating an electromagnetic wave toward the electromagnetic wave thermal conversion material to expand a portion, corresponding to the first pattern, of the expansion layer, and a second step including forming a second pattern including a coarser pattern than the first pattern using an electromagnetic wave thermal conversion material on a second surface, on the opposite side to the side on which the expansion layer is provided, of the medium and then irradiating an electromagnetic wave toward the electromagnetic wave thermal conversion material to expand a portion, corresponding to the second pattern, of the expansion layer.