A three-dimensional distance measurement apparatus, comprising: a three-dimensional imaging unit including a plurality of image pickup devices adapted to image an image and a rotation drive device adapted to rotate the image pickup devices and adjust optical axes such that reflections of an object to be measured in a space to be measured have a predetermined amount of overlap; an association calculating unit adapted to calculate position association information in which pixel positions at a time when a required measurement point in the space to be measured is mapped onto a plurality of the images are associated; a three-dimensional shape calculating unit adapted to calculate a three-dimensional shape based on three-dimensional coordinates of the object to be measured, using the position association information and rotational information obtained from the rotation drive device; a three-dimensional shape estimation calculating unit adapted to estimate, from the three-dimensional shape obtained from the three-dimensional shape calculating unit, a three-dimensional shape of a region of the object to be measured where the three-dimensional shape is not obtained; a three-dimensional measurement coordinates calculating unit adapted to calculate three-dimensional coordinates of two distance measurement points designated on the object to be measured, from an estimation result obtained from the three-dimensional shape estimation calculating unit; a distance calculating unit adapted to calculate a distance between the two points using the three-dimensional coordinates obtained from the three-dimensional measurement coordinates calculating unit, and a design drawing information recording unit adapted to record design drawing information such as length and diameter of the object to be measured, wherein the three-dimensional shape estimation calculating unit is configured to estimate a three-dimensional shape of the object to be measured by comparing the design drawing information with the three-dimensional shape. a three-dimensional imaging unit including a plurality of image pickup devices adapted to image an image and a rotation drive device adapted to rotate the image pickup devices and adjust optical axes such that reflections of an object to be measured in a space to be measured have a predetermined amount of overlap; an association calculating unit adapted to calculate position association information in which pixel positions at a time when a required measurement point in the space to be measured is mapped onto a plurality of the images are associated; a three-dimensional shape calculating unit adapted to calculate a three-dimensional shape based on three-dimensional coordinates of the object to be measured, using the position association information and rotational information obtained from the rotation drive device; a three-dimensional shape estimation calculating unit adapted to estimate, from the three-dimensional shape obtained from the three-dimensional shape calculating unit, a three-dimensional shape of a region of the object to be measured where the three-dimensional shape is not obtained; a three-dimensional measurement coordinates calculating unit adapted to calculate three-dimensional coordinates of two distance measurement points designated on the object to be measured, from an estimation result obtained from the three-dimensional shape estimation calculating unit; a distance calculating unit adapted to calculate a distance between the two points using the three-dimensional coordinates obtained from the three-dimensional measurement coordinates calculating unit, and a design drawing information recording unit adapted to record design drawing information such as length and diameter of the object to be measured, wherein the three-dimensional shape estimation calculating unit is configured to estimate a three-dimensional shape of the object to be measured by comparing the design drawing information with the three-dimensional shape.