To quickly and accurately measure elevation of a structure formed dispersively.

A device comprises a moving means (21) for moving a focus position of an objective lens (8) to the light axis direction; a first focusing optical system which constitutes a common focus optical system irradiating an object to be measured (9) with light through the objective lens, relatively moving the object to be measured and the objective lens to the light axis direction by means of the moving means, and gaining the reflection light from the object to be measured as a sectioning image; and a second focusing optical system for focusing the sectioning image by the first focusing optical system on an imaging means (12). From the relation between the focal point and the brightness value by integrating the outputs of a plurality of pixels of the imaging means including a bright point center where the reflection light from near the top of the structure or the predetermined center position of the structure, the elevation of the object to be measured is obtained.