[Problem] When the inclination of an object surface reaches or exceeds a certain level, direct light consisting of a specularly reflected light component leaves the range of the solid observation angle formed by the observation optical system, and it becomes difficult to continuously and quantitatively obtain the surface shape of the object surface.
[Solution] This invention emits emission light capable of, within an observation range for an object under inspection, simultaneously forming the same solid emission angle on each point on an object surface regardless of the distance from the illumination; for a non-continuous area where direct light is not returned, uses variation in the solid angle of direct light unique to the vicinity of the non-continuous area to make it possible to at least measure height-direction variation of the non-continuous area; and uses brightness information indicating variation in a scattered light component of object light from the non-continuous area to make it possible to continuously acquire the three-dimensional shape of the non-continuous area.