An optical three-dimensional structure measuring device including: optical three-dimensional structure information storing device (91) for storing optical three-dimensional structure information; specific layer extracting device (121) for comparing information values of the optical three-dimensional structure information stored in the optical three-dimensional structure information storing device with a predetermined threshold and extracting, as a specific layer area of the measurement target, an area equal to or greater than a predetermined range where the information values of the optical three-dimensional structure information equal to or greater than the predetermined threshold continue; missing area extracting device (122) for extracting, as missing areas, areas where the information values of the optical three-dimensional structure information are smaller than the predetermined threshold in the specific layer area; missing area range calculating device (123) for calculating sizes of ranges of the missing areas; and region-of-interest classifying device (124) for comparing the sizes of the ranges of the missing areas with a plurality of predetermined range determination reference values and classifying the missing areas into a plurality of types of regions of interest.