A film structure includes a first metal layer, a second metal layer, and an insulation layer located between the first metal layer and the second metal layer. In at least a portion of an edge region of the film structure, the first metal layer extends outwards relative to an edge of the insulation layer by a first predetermined length, and the insulation layer extends outwards relative to an edge of the second metal layer by a second predetermined length. In this way, when the film structure is measured, a fall value between the surface, adjacent to the second metal layer, of the insulation layer and the surface, adjacent to the insulation layer, of the first metal layer is measured by means of a motion trajectory of the measuring probe at the time of ascending or descending, thereby obtaining a more accurate thickness value of the insulation layer.