A position posture identification device includes: an actual measurement data acquisition unit which acquires actual measurement data on the shape of a workpiece; a virtual measurement data generation unit which generates, from shape data defined for the workpiece, virtual measurement data; a filter processing unit which performs, based on the measurement property of the three-dimensional measuring machine, affine transformation on the virtual measurement data; a feature point extraction unit which extracts feature point data from the actual measurement data and the virtual measurement data; a storage unit which stores, as model data of the workpiece, the feature point data extracted from the virtual measurement data; and a position posture calculation unit which checks the feature point data of the actual measurement data against data obtained by performing coordinate transformation on the feature point data included in the model data so as to calculate the position posture of the workpiece.