To provide a three-dimensional information acquiring system that is shortened in fetching time.

This three-dimensional information acquiring system acquires the tree-dimensional information on an object 2 by projecting a luminous flux imparted with a spatial index upon the object 2, and analyzing the image of the object 2 acquired by means of an image pickup device. The image pickup device is provided with a photographic lens 3 which forms the intermediate image 4 of the object 2, a lens array 5 which forms the image of the intermediate image 4 on an image pickup element 6 as a plurality of secondary images 8, and an optical filter 7 installed in its optical path.